text: /*******************************************************************************
    USB Device Layer
  
    Company:
      Microchip Technology Inc.
  
    File Name:
      usb_device.c
  
    Summary:
     Provides basic USB device functionality, including enumeration and USB
     chapter 9 required behavior.
  
    Description:
     Provides basic USB device functionality, including enumeration and USB
     chapter 9 required behavior.
  *******************************************************************************/
  
  // DOM-IGNORE-BEGIN
  /*******************************************************************************
      (c) 2022 Microchip Technology Inc. and its subsidiaries.
  
      Subject to your compliance with these terms, you may use Microchip
      software and any derivatives exclusively with Microchip products. It is
      your responsibility to comply with third party license terms applicable to
      your use of third party software (including open source software) that may
      accompany Microchip software.
  
      THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES, WHETHER
      EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE, INCLUDING ANY
      IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, AND FITNESS
      FOR A PARTICULAR PURPOSE.
  
      IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE,
      INCIDENTAL OR CONSEQUENTIAL LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND
      WHATSOEVER RELATED TO THE SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP
      HAS BEEN ADVISED OF THE POSSIBILITY OR THE DAMAGES ARE FORESEEABLE. TO
      THE FULLEST EXTENT ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL
      CLAIMS IN ANY WAY RELATED TO THIS SOFTWARE WILL NOT EXCEED THE AMOUNT
      OF FEES, IF ANY, THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS
      SOFTWARE.
  *******************************************************************************/
  // DOM-IGNORE-END
  
  
  // *****************************************************************************
  // *****************************************************************************
  // Section: Included Files
  // *****************************************************************************
  // *****************************************************************************
  #include <stdint.h>
  #include <stddef.h>
  #include "system.h"
  #include "usb_config.h"
  #include "usb.h"
  #include "usb_ch9.h"
  #include "usb_device.h"
  #include "usb_device_local.h"
  
  #if defined(USB_USE_MSD)
      #include "usb_device_msd.h"
  #endif
  
  // *****************************************************************************
  // *****************************************************************************
  // Section: File Scope or Global Constants
  // *****************************************************************************
  // *****************************************************************************
  #if !defined(USE_USB_BUS_SENSE_IO)
      //Assume the +5V VBUS is always present (like it would be in a bus powered
      //only application), unless USE_USB_BUS_SENSE_IO and USB_BUS_SENSE have
      //been properly defined elsewhere in the project.
      #undef USB_BUS_SENSE
      #define USB_BUS_SENSE 1
  #endif
  
  #if defined(USB_DEVICE_DISABLE_DTS_CHECKING)
      #define _DTS_CHECKING_ENABLED 0
  #else
      #define _DTS_CHECKING_ENABLED _DTSEN
  #endif
  
  #if !defined(self_power)
      //Assume the application is always bus powered, unless self_power has been
      //defined elsewhere in the project
      #define self_power 0    //0 = bus powered
  #endif
  
  #if !defined(USB_MAX_NUM_CONFIG_DSC)
      //Assume the application only implements one configuration descriptor,
      //unless otherwise specified elsewhere in the project
      #define USB_MAX_NUM_CONFIG_DSC      1
  #endif
  
  #if defined(__XC8)
      //Suppress expected/harmless compiler warning message about unused RAM variables.
      //Certain variables are not used if you don't use all of the USB stack APIs.
      //These variables should not be removed (since they are still used/needed in
      //some applications).
      #pragma warning disable 1090
  #endif
  
  // *****************************************************************************
  // *****************************************************************************
  // Section: File Scope Data Types
  // *****************************************************************************
  // *****************************************************************************
  typedef union
  {
      uint8_t Val;
      struct __PACKED
      {
          unsigned b0:1;
          unsigned b1:1;
          unsigned b2:1;
          unsigned b3:1;
          unsigned b4:1;
          unsigned b5:1;
          unsigned b6:1;
          unsigned b7:1;
      } bits;
  } uint8_t_VAL, uint8_t_BITS;
  
  // *****************************************************************************
  // *****************************************************************************
  // Section: Variables
  // *****************************************************************************
  // *****************************************************************************
  USB_VOLATILE USB_DEVICE_STATE USBDeviceState;
  USB_VOLATILE uint8_t USBActiveConfiguration;
  USB_VOLATILE uint8_t USBAlternateInterface[USB_MAX_NUM_INT];
  volatile BDT_ENTRY *pBDTEntryEP0OutCurrent;
  volatile BDT_ENTRY *pBDTEntryEP0OutNext;
  volatile BDT_ENTRY *pBDTEntryOut[USB_MAX_EP_NUMBER+1];
  volatile BDT_ENTRY *pBDTEntryIn[USB_MAX_EP_NUMBER+1];
  USB_VOLATILE uint8_t shortPacketStatus;
  USB_VOLATILE uint8_t controlTransferState;
  USB_VOLATILE IN_PIPE inPipes[1];
  USB_VOLATILE OUT_PIPE outPipes[1];
  USB_VOLATILE uint8_t *pDst;
  USB_VOLATILE bool RemoteWakeup;
  USB_VOLATILE bool USBBusIsSuspended;
  USB_VOLATILE USTAT_FIELDS USTATcopy;
  USB_VOLATILE uint8_t endpoint_number;
  USB_VOLATILE bool BothEP0OutUOWNsSet;
  USB_VOLATILE EP_STATUS ep_data_in[USB_MAX_EP_NUMBER+1];
  USB_VOLATILE EP_STATUS ep_data_out[USB_MAX_EP_NUMBER+1];
  USB_VOLATILE uint8_t USBStatusStageTimeoutCounter;
  volatile bool USBDeferStatusStagePacket;
  volatile bool USBStatusStageEnabledFlag1;
  volatile bool USBStatusStageEnabledFlag2;
  volatile bool USBDeferINDataStagePackets;
  volatile bool USBDeferOUTDataStagePackets;
  
  /** USB FIXED LOCATION VARIABLES ***********************************/
  #if defined(COMPILER_MPLAB_C18)
      #pragma udata USB_BDT=USB_BDT_ADDRESS
  #endif
  
  volatile BDT_ENTRY BDT[BDT_NUM_ENTRIES] BDT_BASE_ADDR_TAG;
  
  /********************************************************************
   * EP0 Buffer Space
   *******************************************************************/
  volatile CTRL_TRF_SETUP SetupPkt CTRL_TRF_SETUP_ADDR_TAG;
  volatile uint8_t CtrlTrfData[USB_EP0_BUFF_SIZE] CTRL_TRF_DATA_ADDR_TAG;
  
  /********************************************************************
   * non-EP0 Buffer Space
   *******************************************************************/
  #if defined(USB_USE_MSD)
      //Check if the MSD application specific USB endpoint buffer placement address 
      //macros have already been defined or not (ex: in a processor specific header)
      //The msd_cbw and msd_csw buffers must be USB module accessible (and therefore
      //must be at a certain address range on certain microcontrollers).
      #if !defined(MSD_CBW_ADDR_TAG)
          //Not previously defined.  Assume in this case all microcontroller RAM is
          //USB module accessible, and therefore, no specific address tag value is needed.
          #define MSD_CBW_ADDR_TAG
          #define MSD_CSW_ADDR_TAG
      #endif
  	volatile USB_MSD_CBW msd_cbw MSD_CBW_ADDR_TAG;  //Must be located in USB module accessible RAM
  	volatile USB_MSD_CSW msd_csw MSD_CSW_ADDR_TAG;  //Must be located in USB module accessible RAM
  
      #if defined(__18CXX) || defined(__XC8)
          volatile char msd_buffer[512] @ MSD_BUFFER_ADDRESS;
      #else
          volatile char msd_buffer[512];
  	#endif
  #endif
  
  //Depricated in v2.2 - will be removed in a future revision
  #if !defined(USB_USER_DEVICE_DESCRIPTOR)
      //Device descriptor
      extern const USB_DEVICE_DESCRIPTOR device_dsc;
  #else
      USB_USER_DEVICE_DESCRIPTOR_INCLUDE;
  #endif
  
  #if !defined(USB_USER_CONFIG_DESCRIPTOR)
      //Array of configuration descriptors
      extern const uint8_t *const USB_CD_Ptr[];
  #else
      USB_USER_CONFIG_DESCRIPTOR_INCLUDE;
  #endif
  
  extern const uint8_t *const USB_SD_Ptr[];
  
  
  // *****************************************************************************
  // *****************************************************************************
  // Section: Private and External Prototypes
  // *****************************************************************************
  // *****************************************************************************
  extern bool USER_USB_CALLBACK_EVENT_HANDLER(USB_EVENT event, void *pdata, uint16_t size);
  
  static void USBCtrlEPService(void);
  static void USBCtrlTrfSetupHandler(void);
  static void USBCtrlTrfInHandler(void);
  static void USBCheckStdRequest(void);
  static void USBStdGetDscHandler(void);
  static void USBCtrlEPServiceComplete(void);
  static void USBCtrlTrfTxService(void);
  static void USBCtrlTrfRxService(void);
  static void USBStdSetCfgHandler(void);
  static void USBStdGetStatusHandler(void);
  static void USBStdFeatureReqHandler(void);
  static void USBCtrlTrfOutHandler(void);
  static void USBConfigureEndpoint(uint8_t EPNum, uint8_t direction);
  static void USBWakeFromSuspend(void);
  static void USBSuspend(void);
  static void USBStallHandler(void);
  
  // *****************************************************************************
  // *****************************************************************************
  // Section: Macros or Functions
  // *****************************************************************************
  // *****************************************************************************
  
  /****************************************************************************
    Function:
      void USBAdvancePingPongBuffer(BDT_ENTRY** buffer)
  
    Description:
      This function will advance the passed pointer to the next buffer based on
      the ping pong option setting.  This function should be used for EP1-EP15
      only.  This function is not valid for EP0.
  
    Precondition:
      None
  
    Parameters:
      BDT_ENTRY** - pointer to the BDT_ENTRY pointer that you want to be advanced
      to the next buffer state
  
    Return Values:
      None
  
    Remarks:
      None
  
    ***************************************************************************/
  #define USBAdvancePingPongBuffer(buffer) {((uint8_t_VAL*)buffer)->Val ^= USB_NEXT_PING_PONG;}
  #define USBHALPingPongSetToOdd(buffer)   {((uint8_t_VAL*)buffer)->Val |= USB_NEXT_PING_PONG;}
  #define USBHALPingPongSetToEven(buffer)  {((uint8_t_VAL*)buffer)->Val &= ~USB_NEXT_PING_PONG;}
  
  
  /**************************************************************************
      Function:
          void USBDeviceInit(void)
      
      Description:
          This function initializes the device stack it in the default state. The
          USB module will be completely reset including all of the internal
          variables, registers, and interrupt flags.
                  
      Precondition:
          This function must be called before any of the other USB Device
          functions can be called, including USBDeviceTasks().
          
      Parameters:
          None
       
      Return Values:
          None
          
      Remarks:
          None
                                                            
    ***************************************************************************/
  void USBDeviceInit(void)
  {
      uint8_t i;
  
      USBDisableInterrupts();
  
      // Clear all USB error flags
      USBClearInterruptRegister(U1EIR);  
         
      // Clears all USB interrupts          
      USBClearInterruptRegister(U1IR); 
  
      //Clear all of the endpoint control registers
      U1EP0 = 0;
      
      DisableNonZeroEndpoints(USB_MAX_EP_NUMBER);
  
      SetConfigurationOptions();
  
      //power up the module (if not already powered)
      USBPowerModule();
  
      //set the address of the BDT (if applicable)
      USBSetBDTAddress(BDT);
  
      //Clear all of the BDT entries
      for(i=0;i<(sizeof(BDT)/sizeof(BDT_ENTRY));i++)
      {
          BDT[i].Val = 0x00;
      }
  
      // Assert reset request to all of the Ping Pong buffer pointers
      USBPingPongBufferReset = 1;                    
  
      // Reset to default address
      U1ADDR = 0x00;                   
  
      // Make sure packet processing is enabled
      USBPacketDisable = 0;           
  
      //Stop trying to reset ping pong buffer pointers
      USBPingPongBufferReset = 0;
  
      // Flush any pending transactions
      while(USBTransactionCompleteIF == 1)      
      {
          USBClearInterruptFlag(USBTransactionCompleteIFReg,USBTransactionCompleteIFBitNum);
          //Initialize USB stack software state variables
          inPipes[0].info.Val = 0;
          outPipes[0].info.Val = 0;
          outPipes[0].wCount.Val = 0;
      }
  
      //Set flags to true, so the USBCtrlEPAllowStatusStage() function knows not to
      //try and arm a status stage, even before the first control transfer starts.
      USBStatusStageEnabledFlag1 = true;
      USBStatusStageEnabledFlag2 = true;
      //Initialize other flags
      USBDeferINDataStagePackets = false;
      USBDeferOUTDataStagePackets = false;
      USBBusIsSuspended = false;
  
      //Initialize all pBDTEntryIn[] and pBDTEntryOut[]
      //pointers to NULL, so they don't get used inadvertently.
      for(i = 0; i < (uint8_t)(USB_MAX_EP_NUMBER+1u); i++)
      {
          pBDTEntryIn[i] = 0u;
          pBDTEntryOut[i] = 0u;
          ep_data_in[i].Val = 0u;
          ep_data_out[i].Val = 0u;
      }
  
      //Get ready for the first packet
      pBDTEntryIn[0] = (volatile BDT_ENTRY*)&BDT[EP0_IN_EVEN];
      // Initialize EP0 as a Ctrl EP
      U1EP0 = EP_CTRL|USB_HANDSHAKE_ENABLED;        
  	//Prepare for the first SETUP on EP0 OUT
      BDT[EP0_OUT_EVEN].ADR = ConvertToPhysicalAddress(&SetupPkt);
      BDT[EP0_OUT_EVEN].CNT = USB_EP0_BUFF_SIZE;
      BDT[EP0_OUT_EVEN].STAT.Val = _DAT0|_BSTALL;
      BDT[EP0_OUT_EVEN].STAT.Val |= _USIE;
  
      // Clear active configuration
      USBActiveConfiguration = 0;     
  
      //Indicate that we are now in the detached state        
      USBDeviceState = DETACHED_STATE;
  }
  
  /**************************************************************************
    Function:
          void USBDeviceTasks(void)
      
    Summary:
      This function is the main state machine/transaction handler of the USB 
      device side stack.  When the USB stack is operated in "USB_POLLING" mode 
      (usb_config.h user option) the USBDeviceTasks() function should be called 
      periodically to receive and transmit packets through the stack. This 
      function also takes care of control transfers associated with the USB 
      enumeration process, and detecting various USB events (such as suspend).  
      This function should be called at least once every 1.8ms during the USB 
      enumeration process. After the enumeration process is complete (which can 
      be determined when USBGetDeviceState() returns CONFIGURED_STATE), the 
      USBDeviceTasks() handler may be called the faster of: either once 
      every 9.8ms, or as often as needed to make sure that the hardware USTAT 
      FIFO never gets full.  A good rule of thumb is to call USBDeviceTasks() at
      a minimum rate of either the frequency that USBTransferOnePacket() gets 
      called, or, once/1.8ms, whichever is faster.  See the inline code comments 
      near the top of usb_device.c for more details about minimum timing 
      requirements when calling USBDeviceTasks().
      
      When the USB stack is operated in "USB_INTERRUPT" mode, it is not necessary
      to call USBDeviceTasks() from the main loop context.  In the USB_INTERRUPT
      mode, the USBDeviceTasks() handler only needs to execute when a USB 
      interrupt occurs, and therefore only needs to be called from the interrupt 
      context.
  
    Description:
      This function is the main state machine/transaction handler of the USB 
      device side stack.  When the USB stack is operated in "USB_POLLING" mode 
      (usb_config.h user option) the USBDeviceTasks() function should be called 
      periodically to receive and transmit packets through the stack. This 
      function also takes care of control transfers associated with the USB 
      enumeration process, and detecting various USB events (such as suspend).  
      This function should be called at least once every 1.8ms during the USB 
      enumeration process. After the enumeration process is complete (which can 
      be determined when USBGetDeviceState() returns CONFIGURED_STATE), the 
      USBDeviceTasks() handler may be called the faster of: either once 
      every 9.8ms, or as often as needed to make sure that the hardware USTAT 
      FIFO never gets full.  A good rule of thumb is to call USBDeviceTasks() at
      a minimum rate of either the frequency that USBTransferOnePacket() gets 
      called, or, once/1.8ms, whichever is faster.  See the inline code comments 
      near the top of usb_device.c for more details about minimum timing 
      requirements when calling USBDeviceTasks().
      
      When the USB stack is operated in "USB_INTERRUPT" mode, it is not necessary
      to call USBDeviceTasks() from the main loop context.  In the USB_INTERRUPT
      mode, the USBDeviceTasks() handler only needs to execute when a USB 
      interrupt occurs, and therefore only needs to be called from the interrupt 
      context.
  
      Typical usage:
      <code>
      void main(void)
      {
          USBDeviceInit();
          while(1)
          {
              USBDeviceTasks(); //Takes care of enumeration and other USB events
              if((USBGetDeviceState() \< CONFIGURED_STATE) ||
                 (USBIsDeviceSuspended() == true))
              {
                  //Either the device is not configured or we are suspended,
                  // so we don't want to execute any USB related application code
                  continue;   //go back to the top of the while loop
              }
              else
              {
                  //Otherwise we are free to run USB and non-USB related user 
                  //application code.
                  UserApplication();
              }
          }
      }
      </code>
  
    Precondition:
      Make sure the USBDeviceInit() function has been called prior to calling
      USBDeviceTasks() for the first time.
    Remarks:
      USBDeviceTasks() does not need to be called while in the USB suspend mode, 
      if the user application firmware in the USBCBSuspend() callback function
      enables the ACTVIF USB interrupt source and put the microcontroller into 
      sleep mode.  If the application firmware decides not to sleep the 
      microcontroller core during USB suspend (ex: continues running at full 
      frequency, or clock switches to a lower frequency), then the USBDeviceTasks()
      function must still be called periodically, at a rate frequent enough to 
      ensure the 10ms resume recovery interval USB specification is met.  Assuming
      a worst case primary oscillator and PLL start up time of less than 5ms, then
      USBDeviceTasks() should be called once every 5ms in this scenario.
     
      When the USB cable is detached, or the USB host is not actively powering 
      the VBUS line to +5V nominal, the application firmware does not always have 
      to call USBDeviceTasks() frequently, as no USB activity will be taking 
      place.  However, if USBDeviceTasks() is not called regularly, some 
      alternative means of promptly detecting when VBUS is powered (indicating 
      host attachment), or not powered (host powered down or USB cable unplugged)
      is still needed.  For self or dual self/bus powered USB applications, see 
      the USBDeviceAttach() and USBDeviceDetach() API documentation for additional 
      considerations.
      ***************************************************************************/
  void USBDeviceTasks(void)
  {
      uint8_t i;
  
  #ifdef USB_SUPPORT_OTG
      //SRP Time Out Check
      if (USBOTGSRPIsReady())
      {
          if (USBT1MSECIF && USBT1MSECIE)
          {
              if (USBOTGGetSRPTimeOutFlag())
              {
                  if (USBOTGIsSRPTimeOutExpired())
                  {
                      USB_OTGEventHandler(0,OTG_EVENT_SRP_FAILED,0,0);
                  }       
              }
  
              //Clear Interrupt Flag
              USBClearInterruptFlag(USBT1MSECIFReg,USBT1MSECIFBitNum);
          }
      }
  #endif
  
      #if defined(USB_POLLING)
      //If the interrupt option is selected then the customer is required
      //  to notify the stack when the device is attached or removed from the
      //  bus by calling the USBDeviceAttach() and USBDeviceDetach() functions.
      if (USB_BUS_SENSE != 1)
      {
           // Disable module & detach from bus
           U1CON = 0;             
  
           // Mask all USB interrupts              
           U1IE = 0;          
  
           //Move to the detached state                  
           USBDeviceState = DETACHED_STATE;
  
           #ifdef  USB_SUPPORT_OTG    
               //Disable D+ Pullup
               U1OTGCONbits.DPPULUP = 0;
  
               //Disable HNP
               USBOTGDisableHnp();
  
               //Deactivate HNP
               USBOTGDeactivateHnp();
               
               //If ID Pin Changed State
               if (USBIDIF && USBIDIE)
               {  
                   //Re-detect & Initialize
                    USBOTGInitialize();
  
                    //Clear ID Interrupt Flag
                    USBClearInterruptFlag(USBIDIFReg,USBIDIFBitNum);
               }
           #endif
  
           #if defined __C30__ || defined __XC16__
               //USBClearInterruptFlag(U1OTGIR, 3); 
           #endif
              //return so that we don't go through the rest of 
              //the state machine
           USBClearUSBInterrupt();
           return;
      }
  
  	#ifdef USB_SUPPORT_OTG
      //If Session Is Started Then
      else
  	{
          //If SRP Is Ready
          if (USBOTGSRPIsReady())
          {   
              //Clear SRPReady
              USBOTGClearSRPReady();
  
              //Clear SRP Timeout Flag
              USBOTGClearSRPTimeOutFlag();
  
              //Indicate Session Started
              UART2PrintString( "\r\n***** USB OTG B Event - Session Started  *****\r\n" );
          }
      }
  	#endif	//#ifdef USB_SUPPORT_OTG
  
      //if we are in the detached state
      if(USBDeviceState == DETACHED_STATE)
      {
  	    //Initialize register to known value
          U1CON = 0;                          
  
          // Mask all USB interrupts
          U1IE = 0;                                
  
          //Enable/set things like: pull ups, full/low-speed mode, 
          //set the ping pong mode, and set internal transceiver
          SetConfigurationOptions();
  
          // Enable module & attach to bus
          while(!U1CONbits.USBEN){U1CONbits.USBEN = 1;}
  
          //moved to the attached state
          USBDeviceState = ATTACHED_STATE;
  
          #ifdef  USB_SUPPORT_OTG
              U1OTGCON |= USB_OTG_DPLUS_ENABLE | USB_OTG_ENABLE;  
          #endif
      }
  	#endif  //#if defined(USB_POLLING)
  
      if(USBDeviceState == ATTACHED_STATE)
      {
          /*
           * After enabling the USB module, it takes some time for the
           * voltage on the D+ or D- line to rise high enough to get out
           * of the SE0 condition. The USB Reset interrupt should not be
           * unmasked until the SE0 condition is cleared. This helps
           * prevent the firmware from misinterpreting this unique event
           * as a USB bus reset from the USB host.
           */
  
          if(!USBSE0Event)
          {
              USBClearInterruptRegister(U1IR);// Clear all USB interrupts
              #if defined(USB_POLLING)
                  U1IE=0;                        // Mask all USB interrupts
              #endif
              USBResetIE = 1;             // Unmask RESET interrupt
              USBIdleIE = 1;             // Unmask IDLE interrupt
              USBDeviceState = POWERED_STATE;
          }
      }
  
      #ifdef  USB_SUPPORT_OTG
          //If ID Pin Changed State
          if (USBIDIF && USBIDIE)
          {  
              //Re-detect & Initialize
              USBOTGInitialize();
  
              USBClearInterruptFlag(USBIDIFReg,USBIDIFBitNum);
          }
      #endif
  
      /*
       * Task A: Service USB Activity Interrupt
       */
      if(USBActivityIF && USBActivityIE)
      {
          USBClearInterruptFlag(USBActivityIFReg,USBActivityIFBitNum);
          #if defined(USB_SUPPORT_OTG)
              U1OTGIR = 0x10;        
          #else
              USBWakeFromSuspend();
          #endif
      }
  
      /*
       * Pointless to continue servicing if the device is in suspend mode.
       */
      if(USBSuspendControl==1)
      {
          USBClearUSBInterrupt();
          return;
      }
  
      /*
       * Task B: Service USB Bus Reset Interrupt.
       * When bus reset is received during suspend, ACTVIF will be set first,
       * once the UCONbits.SUSPND is clear, then the URSTIF bit will be asserted.
       * This is why URSTIF is checked after ACTVIF.
       *
       * The USB reset flag is masked when the USB state is in
       * DETACHED_STATE or ATTACHED_STATE, and therefore cannot
       * cause a USB reset event during these two states.
       */
      if(USBResetIF && USBResetIE)
      {
          USBDeviceInit();
  
          //Re-enable the interrupts since the USBDeviceInit() function will
          //  disable them.  This will do nothing in a polling setup
          USBUnmaskInterrupts();
  
          USBDeviceState = DEFAULT_STATE;
  
          #ifdef USB_SUPPORT_OTG
               //Disable HNP
               USBOTGDisableHnp();
  
               //Deactivate HNP
               USBOTGDeactivateHnp();
          #endif
  
          USBClearInterruptFlag(USBResetIFReg,USBResetIFBitNum);
      }
  
      /*
       * Task C: Service other USB interrupts
       */
      if(USBIdleIF && USBIdleIE)
      { 
          #ifdef  USB_SUPPORT_OTG 
              //If Suspended, Try to switch to Host
              USBOTGSelectRole(ROLE_HOST);
          #else
              USBSuspend();
          #endif
          
          USBClearInterruptFlag(USBIdleIFReg,USBIdleIFBitNum);
      }
  
      if(USBSOFIF)
      {
          if(USBSOFIE)
          {
              USB_SOF_HANDLER(EVENT_SOF,0,1);
          }    
          USBClearInterruptFlag(USBSOFIFReg,USBSOFIFBitNum);
          
          #if defined(USB_ENABLE_STATUS_STAGE_TIMEOUTS)
              //Supporting this feature requires a 1ms timebase for keeping track of the timeout interval.
              #if(USB_SPEED_OPTION == USB_LOW_SPEED)
                  #warning "Double click this message.  See inline code comments."
                  //The "USB_ENABLE_STATUS_STAGE_TIMEOUTS" feature is optional and is
                  //not strictly needed in all applications (ex: those that never call 
                  //USBDeferStatusStage() and don't use host to device (OUT) control
                  //transfers with data stage).  
                  //However, if this feature is enabled and used, it requires a timer 
                  //(preferrably 1ms) to decrement the USBStatusStageTimeoutCounter.  
                  //In USB Full Speed applications, the host sends Start-of-Frame (SOF) 
                  //packets at a 1ms rate, which generates SOFIF interrupts.
                  //These interrupts can be used to decrement USBStatusStageTimeoutCounter as shown 
                  //below.  However, the host does not send SOF packets to Low Speed devices.  
                  //Therefore, some other method  (ex: using a general purpose microcontroller 
                  //timer, such as Timer0) needs to be implemented to call and execute the below code
                  //at a once/1ms rate, in a low speed USB application.
                  //Note: Pre-condition to executing the below code: USBDeviceInit() should have
                  //been called at least once (since the last microcontroller reset/power up), 
                  //prior to executing the below code.
              #endif
              
              //Decrement our status stage counter.
              if(USBStatusStageTimeoutCounter != 0u)
              {
                  USBStatusStageTimeoutCounter--;
              }
              //Check if too much time has elapsed since progress was made in 
              //processing the control transfer, without arming the status stage.  
              //If so, auto-arm the status stage to ensure that the control 
              //transfer can [eventually] complete, within the timing limits
              //dictated by section 9.2.6 of the official USB 2.0 specifications.
              if(USBStatusStageTimeoutCounter == 0)
              {
                  USBCtrlEPAllowStatusStage();    //Does nothing if the status stage was already armed.
              } 
          #endif
      }
  
      if(USBStallIF && USBStallIE)
      {
          USBStallHandler();
      }
  
      if(USBErrorIF && USBErrorIE)
      {
          USB_ERROR_HANDLER(EVENT_BUS_ERROR,0,1);
          USBClearInterruptRegister(U1EIR);               // This clears UERRIF
  
          //On PIC18, clearing the source of the error will automatically clear
          //  the interrupt flag.  On other devices the interrupt flag must be 
          //  manually cleared. 
          #if defined(__C32__) || defined(__C30__) || defined __XC16__
              USBClearInterruptFlag( USBErrorIFReg, USBErrorIFBitNum );
          #endif
      }
  
      /*
       * Pointless to continue servicing if the host has not sent a bus reset.
       * Once bus reset is received, the device transitions into the DEFAULT
       * state and is ready for communication.
       */
      if(USBDeviceState < DEFAULT_STATE)
      {
          USBClearUSBInterrupt();
          return;
      }  
  
      /*
       * Task D: Servicing USB Transaction Complete Interrupt
       */
      if(USBTransactionCompleteIE)
      {
          for(i = 0; i < 4u; i++)	//Drain or deplete the USAT FIFO entries.  If the USB FIFO ever gets full, USB bandwidth
          {						//utilization can be compromised, and the device won't be able to receive SETUP packets.
              if(USBTransactionCompleteIF)
              {
                  //Save and extract USTAT register info.  Will use this info later.
                  USTATcopy.Val = U1STAT;
                  endpoint_number = USBHALGetLastEndpoint(USTATcopy);
  
                  USBClearInterruptFlag(USBTransactionCompleteIFReg,USBTransactionCompleteIFBitNum);
  
                  //Keep track of the hardware ping pong state for endpoints other
                  //than EP0, if ping pong buffering is enabled.
                  #if (USB_PING_PONG_MODE == USB_PING_PONG__ALL_BUT_EP0) || (USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG)
                  if(USBHALGetLastDirection(USTATcopy) == OUT_FROM_HOST)
                  {
                      ep_data_out[endpoint_number].bits.ping_pong_state ^= 1;
                  }
                  else
                  {
                      ep_data_in[endpoint_number].bits.ping_pong_state ^= 1;
                  }
                  #endif
  
                  //USBCtrlEPService only services transactions over EP0.
                  //It ignores all other EP transactions.
                  if(endpoint_number == 0)
                  {
                      USBCtrlEPService();
                  }
                  else
                  {
                      USB_TRANSFER_COMPLETE_HANDLER(EVENT_TRANSFER, (uint8_t*)&USTATcopy.Val, 0);
                  }
              }//end if(USBTransactionCompleteIF)
              else
              {
                  break;	//USTAT FIFO must be empty.
              }
          }//end for()
      }//end if(USBTransactionCompleteIE)
  
      USBClearUSBInterrupt();
  }//end of USBDeviceTasks()
  
  /*******************************************************************************
    Function:
          void USBEnableEndpoint(uint8_t ep, uint8_t options)
      
    Summary:
      This function will enable the specified endpoint with the specified
      options
    Description:
      This function will enable the specified endpoint with the specified
      options.
      
      Typical Usage:
      <code>
      void USBCBInitEP(void)
      {
          USBEnableEndpoint(MSD_DATA_IN_EP,USB_IN_ENABLED|USB_OUT_ENABLED|USB_HANDSHAKE_ENABLED|USB_DISALLOW_SETUP);
          USBMSDInit();
      }
      </code>
      
      In the above example endpoint number MSD_DATA_IN_EP is being configured
      for both IN and OUT traffic with handshaking enabled. Also since
      MSD_DATA_IN_EP is not endpoint 0 (MSD does not allow this), then we can
      explicitly disable SETUP packets on this endpoint.
    Conditions:
      None
    Input:
      uint8_t ep -       the endpoint to be configured
      uint8_t options -  optional settings for the endpoint. The options should
                      be ORed together to form a single options string. The
                      available optional settings for the endpoint. The
                      options should be ORed together to form a single options
                      string. The available options are the following\:
                      * USB_HANDSHAKE_ENABLED enables USB handshaking (ACK,
                        NAK)
                      * USB_HANDSHAKE_DISABLED disables USB handshaking (ACK,
                        NAK)
                      * USB_OUT_ENABLED enables the out direction
                      * USB_OUT_DISABLED disables the out direction
                      * USB_IN_ENABLED enables the in direction
                      * USB_IN_DISABLED disables the in direction
                      * USB_ALLOW_SETUP enables control transfers
                      * USB_DISALLOW_SETUP disables control transfers
                      * USB_STALL_ENDPOINT STALLs this endpoint
    Return:
      None
    Remarks:
      None                                                                                                          
    *****************************************************************************/
  void USBEnableEndpoint(uint8_t ep, uint8_t options)
  {
      unsigned char* p;
          
      //Use USBConfigureEndpoint() to set up the pBDTEntryIn/Out[ep] pointer and 
      //starting DTS state in the BDT entry.
      if(options & USB_OUT_ENABLED)
      {
          USBConfigureEndpoint(ep, OUT_FROM_HOST);
      }
      if(options & USB_IN_ENABLED)
      {
          USBConfigureEndpoint(ep, IN_TO_HOST);
      }
  
      //Update the relevant UEPx register to actually enable the endpoint with
      //the specified options (ex: handshaking enabled, control transfers allowed,
      //etc.)
      #if defined(__C32__)
          p = (unsigned char*)(&U1EP0+(4*ep));
      #else
          p = (unsigned char*)(&U1EP0+ep);
      #endif
      *p = options;
  }
  
  
  /*************************************************************************
    Function:
      USB_HANDLE USBTransferOnePacket(uint8_t ep, uint8_t dir, uint8_t* data, uint8_t len)
      
    Summary:
      Transfers a single packet (one transaction) of data on the USB bus.
  
    Description:
      The USBTransferOnePacket() function prepares a USB endpoint
      so that it may send data to the host (an IN transaction), or 
      receive data from the host (an OUT transaction).  The 
      USBTransferOnePacket() function can be used both to receive	and 
      send data to the host.  This function is the primary API function 
      provided by the USB stack firmware for sending or receiving application 
      data over the USB port.  
  
      The USBTransferOnePacket() is intended for use with all application 
      endpoints.  It is not used for sending or receiving applicaiton data 
      through endpoint 0 by using control transfers.  Separate API 
      functions, such as USBEP0Receive(), USBEP0SendRAMPtr(), and
      USBEP0SendROMPtr() are provided for this purpose.
  
      The	USBTransferOnePacket() writes to the Buffer Descriptor Table (BDT)
      entry associated with an endpoint buffer, and sets the UOWN bit, which 
      prepares the USB hardware to allow the transaction to complete.  The 
      application firmware can use the USBHandleBusy() macro to check the 
      status of the transaction, to see if the data has been successfully 
      transmitted yet.
  
  
      Typical Usage
      <code>
      //make sure that the we are in the configured state
      if(USBGetDeviceState() == CONFIGURED_STATE)
      {
          //make sure that the last transaction isn't busy by checking the handle
          if(!USBHandleBusy(USBInHandle))
          {
  	        //Write the new data that we wish to send to the host to the INPacket[] array
  	        INPacket[0] = USEFUL_APPLICATION_VALUE1;
  	        INPacket[1] = USEFUL_APPLICATION_VALUE2;
  	        //INPacket[2] = ... (fill in the rest of the packet data)
  	      
              //Send the data contained in the INPacket[] array through endpoint "EP_NUM"
              USBInHandle = USBTransferOnePacket(EP_NUM,IN_TO_HOST,(uint8_t*)&INPacket[0],sizeof(INPacket));
          }
      }
      </code>
  
    Conditions:
      Before calling USBTransferOnePacket(), the following should be true.
      1.  The USB stack has already been initialized (USBDeviceInit() was called).
      2.  A transaction is not already pending on the specified endpoint.  This
          is done by checking the previous request using the USBHandleBusy() 
          macro (see the typical usage example).
      3.  The host has already sent a set configuration request and the 
          enumeration process is complete.
          This can be checked by verifying that the USBGetDeviceState() 
          macro returns "CONFIGURED_STATE", prior to calling 
          USBTransferOnePacket().
   					
    Input:
      uint8_t ep - The endpoint number that the data will be transmitted or
  	          received on
      uint8_t dir - The direction of the transfer
                 This value is either OUT_FROM_HOST or IN_TO_HOST
      uint8_t* data - For IN transactions: pointer to the RAM buffer containing
                   the data to be sent to the host.  For OUT transactions: pointer
                   to the RAM buffer that the received data should get written to.
     uint8_t len - Length of the data needing to be sent (for IN transactions).
                For OUT transactions, the len parameter should normally be set
                to the endpoint size specified in the endpoint descriptor.    
  
    Return Values:
      USB_HANDLE - handle to the transfer.  The handle is a pointer to 
                   the BDT entry associated with this transaction.  The
                   status of the transaction (ex: if it is complete or still
                   pending) can be checked using the USBHandleBusy() macro
                   and supplying the USB_HANDLE provided by
                   USBTransferOnePacket().
  
    Remarks:
      If calling the USBTransferOnePacket() function from within the USBCBInitEP()
      callback function, the set configuration is still being processed and the
      USBDeviceState may not be == CONFIGURED_STATE yet.  In this	special case, 
      the USBTransferOnePacket() may still be called, but make sure that the 
      endpoint has been enabled and initialized by the USBEnableEndpoint() 
      function first.  
      
    *************************************************************************/
  USB_HANDLE USBTransferOnePacket(uint8_t ep,uint8_t dir,uint8_t* data,uint8_t len)
  {
      volatile BDT_ENTRY* handle;
  
      //If the direction is IN
      if(dir != 0)
      {
          //point to the IN BDT of the specified endpoint
          handle = pBDTEntryIn[ep];
      }
      else
      {
          //else point to the OUT BDT of the specified endpoint
          handle = pBDTEntryOut[ep];
      }
      
      //Error checking code.  Make sure the handle (pBDTEntryIn[ep] or
      //pBDTEntryOut[ep]) is initialized before using it.
      if(handle == 0)
      {
          return 0;
      }
  
      //Toggle the DTS bit if required
      #if (USB_PING_PONG_MODE == USB_PING_PONG__NO_PING_PONG)
          handle->STAT.Val ^= _DTSMASK;
      #elif (USB_PING_PONG_MODE == USB_PING_PONG__EP0_OUT_ONLY)
          if(ep != 0)
          {
              handle->STAT.Val ^= _DTSMASK;
          }
      #endif
  
      //Set the data pointer, data length, and enable the endpoint
      handle->ADR = ConvertToPhysicalAddress(data);
      handle->CNT = len;
      handle->STAT.Val &= _DTSMASK;
      handle->STAT.Val |= (_DTSEN & _DTS_CHECKING_ENABLED);
      handle->STAT.Val |= _USIE;
  
      //Point to the next buffer for ping pong purposes.
      if(dir != OUT_FROM_HOST)
      {
          //toggle over the to the next buffer for an IN endpoint
          USBAdvancePingPongBuffer(&pBDTEntryIn[ep]);      
      }
      else
      {
          //toggle over the to the next buffer for an OUT endpoint
          USBAdvancePingPongBuffer(&pBDTEntryOut[ep]);     
      }
      return (USB_HANDLE)handle;
  }
  
  
  /********************************************************************
      Function:
          void USBStallEndpoint(uint8_t ep, uint8_t dir)
          
      Summary:
           Configures the specified endpoint to send STALL to the host, the next
           time the host tries to access the endpoint.
      
      PreCondition:
          None
          
      Parameters:
          uint8_t ep - The endpoint number that should be configured to send STALL.
          uint8_t dir - The direction of the endpoint to STALL, either
                     IN_TO_HOST or OUT_FROM_HOST.
          
      Return Values:
          None
          
      Remarks:
          None
  
   *******************************************************************/
  void USBStallEndpoint(uint8_t ep, uint8_t dir)
  {
      BDT_ENTRY *p;
  
      if(ep == 0)
      {
          //For control endpoints (ex: EP0), we need to STALL both IN and OUT
          //endpoints.  EP0 OUT must also be prepared to receive the next SETUP 
          //packet that will arrrive.
          pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
          pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&SetupPkt);
          pBDTEntryEP0OutNext->STAT.Val = _DAT0|(_DTSEN & _DTS_CHECKING_ENABLED)|_BSTALL;
          pBDTEntryEP0OutNext->STAT.Val |= _USIE;
          pBDTEntryIn[0]->STAT.Val = _BSTALL; 
          pBDTEntryIn[0]->STAT.Val |= _USIE;
                 
      }
      else
      {
          p = (BDT_ENTRY*)(&BDT[EP(ep,dir,0)]);
          p->STAT.Val |= _BSTALL;
          p->STAT.Val |= _USIE;
      
          //If the device is in FULL or ALL_BUT_EP0 ping pong modes
          //then stall that entry as well
          #if (USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG) || (USB_PING_PONG_MODE == USB_PING_PONG__ALL_BUT_EP0)
          p = (BDT_ENTRY*)(&BDT[EP(ep,dir,1)]);
          p->STAT.Val |= _BSTALL;
          p->STAT.Val |= _USIE;
          #endif
      }
  }
  
  /**************************************************************************
      Function:
          void USBCancelIO(uint8_t endpoint)
      
      Description:
          This function cancels the transfers pending on the specified endpoint.
          This function can only be used after a SETUP packet is received and 
          before that setup packet is handled.  This is the time period in which
          the EVENT_EP0_REQUEST is thrown, before the event handler function
          returns to the stack.
  
      Precondition:
    
      Parameters:
          uint8_t endpoint - the endpoint number you wish to cancel the transfers for
       
      Return Values:
          None
          
      Remarks:
          None
                                                            
    **************************************************************************/
  void USBCancelIO(uint8_t endpoint)
  {
      if(USBPacketDisable == 1)
      {
      	//The PKTDIS bit is currently set right now.  It is therefore "safe"
      	//to mess with the BDT right now.
      	pBDTEntryIn[endpoint]->Val &= _DTSMASK;	//Makes UOWN = 0 (_UCPU mode).  Deactivates endpoint.  Only sends NAKs.
      	pBDTEntryIn[endpoint]->Val ^= _DTSMASK;	//Toggle the DTS bit.  This packet didn't get sent yet, and the next call to USBTransferOnePacket() will re-toggle the DTS bit back to the original (correct) value.
      	
      	//Need to do additional handling if ping-pong buffering is being used
          #if ((USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG) || (USB_PING_PONG_MODE == USB_PING_PONG__ALL_BUT_EP0))
          //Point to the next buffer for ping pong purposes.  UOWN getting cleared
          //(either due to SIE clearing it after a transaction, or the firmware
          //clearing it) makes hardware ping pong pointer advance.
          USBAdvancePingPongBuffer(&pBDTEntryIn[endpoint]);       
      
      	pBDTEntryIn[endpoint]->STAT.Val &= _DTSMASK;
      	pBDTEntryIn[endpoint]->STAT.Val ^= _DTSMASK;
          #endif
      }
  }
  
  /**************************************************************************
      Function:
          void USBDeviceDetach(void)
     
      Summary:
          This function configures the USB module to "soft detach" itself from
          the USB host.
          
      Description:
          This function configures the USB module to perform a "soft detach"
          operation, by disabling the D+ (or D-) ~1.5k pull up resistor, which
          lets the host know the device is present and attached.  This will make
          the host think that the device has been unplugged.  This is potentially
          useful, as it allows the USB device to force the host to re-enumerate
          the device (on the firmware has re-enabled the USB module/pull up, by
          calling USBDeviceAttach(), to "soft re-attach" to the host).
          
      Precondition:
          Should only be called when USB_INTERRUPT is defined.  See remarks
          section if USB_POLLING mode option is being used (usb_config.h option).
  
          Additionally, this function should only be called from the main() loop 
          context.  Do not call this function from within an interrupt handler, as 
          this function may modify global interrupt enable bits and settings.
          
      Parameters:
          None
       
      Return Values:
          None
          
      Remarks:
          If the application firmware calls USBDeviceDetach(), it is strongly
          recommended that the firmware wait at least >= 80ms before calling
          USBDeviceAttach().  If the firmeware performs a soft detach, and then
          re-attaches too soon (ex: after a few micro seconds for instance), some
          hosts may interpret this as an unexpected "glitch" rather than as a
          physical removal/re-attachment of the USB device.  In this case the host
          may simply ignore the event without re-enumerating the device.  To 
          ensure that the host properly detects and processes the device soft
          detach/re-attach, it is recommended to make sure the device remains 
          detached long enough to mimic a real human controlled USB 
          unplug/re-attach event (ex: after calling USBDeviceDetach(), do not
          call USBDeviceAttach() for at least 80+ms, preferrably longer.
          
          Neither the USBDeviceDetach() or USBDeviceAttach() functions are blocking
          or take long to execute.  It is the application firmware's 
          responsibility for adding the 80+ms delay, when using these API 
          functions.
          
          Note: The Windows plug and play event handler processing is fairly 
          slow, especially in certain versions of Windows, and for certain USB
          device classes.  It has been observed that some device classes need to
          provide even more USB detach dwell interval (before calling 
          USBDeviceAttach()), in order to work correctly after re-enumeration.
          If the USB device is a CDC class device, it is recommended to wait
          at least 1.5 seconds or longer, before soft re-attaching to the host,
          to provide the plug and play event handler enough time to finish 
          processing the removal event, before the re-attach occurs.
          
          If the application is using the USB_POLLING mode option, then the 
          USBDeviceDetach() and USBDeviceAttach() functions are not available.  
          In this mode, the USB stack relies on the "#define USE_USB_BUS_SENSE_IO" 
          and "#define USB_BUS_SENSE" options in the 
          HardwareProfile – [platform name].h file. 
  
          When using the USB_POLLING mode option, and the 
          "#define USE_USB_BUS_SENSE_IO" definition has been commented out, then 
          the USB stack assumes that it should always enable the USB module at 
          pretty much all times.  Basically, anytime the application firmware 
          calls USBDeviceTasks(), the firmware will automatically enable the USB 
          module.  This mode would typically be selected if the application was 
          designed to be a purely bus powered device.  In this case, the 
          application is powered from the +5V VBUS supply from the USB port, so 
          it is correct and sensible in this type of application to power up and 
          turn on the USB module, at anytime that the microcontroller is 
          powered (which implies the USB cable is attached and the host is also 
          powered).
  
          In a self powered application, the USB stack is designed with the 
          intention that the user will enable the "#define USE_USB_BUS_SENSE_IO" 
          option in the HardwareProfile – [platform name].h file.  When this 
          option is defined, then the USBDeviceTasks() function will automatically 
          check the I/O pin port value of the designated pin (based on the 
          #define USB_BUS_SENSE option in the HardwareProfile – [platform name].h 
          file), every time the application calls USBDeviceTasks().  If the 
          USBDeviceTasks() function is executed and finds that the pin defined by 
          the #define USB_BUS_SENSE is in a logic low state, then it will 
          automatically disable the USB module and tri-state the D+ and D- pins.  
          If however the USBDeviceTasks() function is executed and finds the pin 
          defined by the #define USB_BUS_SENSE is in a logic high state, then it 
          will automatically enable the USB module, if it has not already been 
          enabled.        
                                                            
    **************************************************************************/
  #if defined(USB_INTERRUPT)
  void USBDeviceDetach(void)
  {
      //If the interrupt option is selected then the customer is required
      //  to notify the stack when the device is attached or removed from the
      //  bus by calling the USBDeviceAttach() and USBDeviceDetach() functions.
  #ifdef USB_SUPPORT_OTG
      if (USB_BUS_SENSE != 1)
  #endif
      {
           // Disable module & detach from bus
           U1CON = 0;             
  
           // Mask all USB interrupts              
           U1IE = 0;          
  
           //Move to the detached state                  
           USBDeviceState = DETACHED_STATE;
  
           #ifdef  USB_SUPPORT_OTG    
               //Disable D+ Pullup
               U1OTGCONbits.DPPULUP = 0;
  
               //Disable HNP
               USBOTGDisableHnp();
  
               //Deactivate HNP
               USBOTGDeactivateHnp();
               
               //If ID Pin Changed State
               if (USBIDIF && USBIDIE)
               {  
                   //Re-detect & Initialize
                    USBOTGInitialize();
  
                    //Clear ID Interrupt Flag
                    USBClearInterruptFlag(USBIDIFReg,USBIDIFBitNum);
               }
           #endif
  
           #if defined __C30__ || defined __XC16__
               //USBClearInterruptFlag(U1OTGIR, 3); 
           #endif
              //return so that we don't go through the rest of 
              //the state machine
            return;
      }
  
  #ifdef USB_SUPPORT_OTG
      //If Session Is Started Then
     else
     {
          //If SRP Is Ready
          if (USBOTGSRPIsReady())
          {   
              //Clear SRPReady
              USBOTGClearSRPReady();
  
              //Clear SRP Timeout Flag
              USBOTGClearSRPTimeOutFlag();
  
              //Indicate Session Started
              UART2PrintString( "\r\n***** USB OTG B Event - Session Started  *****\r\n" );
          }
      }
  #endif
  }
  #endif  //#if defined(USB_INTERRUPT)
  /**************************************************************************
      Function:
          void USBDeviceAttach(void)
      
      Summary:
          Checks if VBUS is present, and that the USB module is not already 
          initalized, and if so, enables the USB module so as to signal device 
          attachment to the USB host.   
  
      Description:
          This function indicates to the USB host that the USB device has been
          attached to the bus.  This function needs to be called in order for the
          device to start to enumerate on the bus.
                  
      Precondition:
          Should only be called when USB_INTERRUPT is defined.  Also, should only 
          be called from the main() loop context.  Do not call USBDeviceAttach()
          from within an interrupt handler, as the USBDeviceAttach() function
          may modify global interrupt enable bits and settings.
  
          For normal USB devices:
          Make sure that if the module was previously on, that it has been turned off 
          for a long time (ex: 100ms+) before calling this function to re-enable the module.
          If the device turns off the D+ (for full speed) or D- (for low speed) ~1.5k ohm
          pull up resistor, and then turns it back on very quickly, common hosts will sometimes 
          reject this event, since no human could ever unplug and reattach a USB device in a 
          microseconds (or nanoseconds) timescale.  The host could simply treat this as some kind 
          of glitch and ignore the event altogether.  
      Parameters:
          None
       
      Return Values:
          None       
      
      Remarks: 
  		See also the USBDeviceDetach() API function documentation.                                                 
  ****************************************************************************/
  #if defined(USB_INTERRUPT)
  void USBDeviceAttach(void)
  {
      //if we are in the detached state
      if(USBDeviceState == DETACHED_STATE)
      {
          if(USB_BUS_SENSE == 1)
          {
      	    //Initialize registers to known states.
              U1CON = 0;          
      
              // Mask all USB interrupts
              U1IE = 0;                                
      
              //Configure things like: pull ups, full/low-speed mode, 
              //set the ping pong mode, and set internal transceiver
              SetConfigurationOptions();
      
              USBEnableInterrupts();  //Modifies global interrupt settings
      
              // Enable module & attach to bus
              while(!U1CONbits.USBEN){U1CONbits.USBEN = 1;}
      
              //moved to the attached state
              USBDeviceState = ATTACHED_STATE;
      
              #ifdef  USB_SUPPORT_OTG
                  U1OTGCON = USB_OTG_DPLUS_ENABLE | USB_OTG_ENABLE;  
              #endif
          }
      }
  }
  #endif  //#if defined(USB_INTERRUPT)
  
  
  /*******************************************************************************
    Function: void USBCtrlEPAllowStatusStage(void);
  
    Summary: This function prepares the proper endpoint 0 IN or endpoint 0 OUT
              (based on the controlTransferState) to allow the status stage packet
              of a control transfer to complete.  This function gets used
              internally by the USB stack itself, but it may also be called from
              the application firmware, IF the application firmware called
              the USBDeferStatusStage() function during the initial processing
              of the control transfer request.  In this case, the application
              must call the USBCtrlEPAllowStatusStage() once, after it has fully
              completed processing and handling the data stage portion of the
              request.
  
              If the application firmware has no need for delaying control
              transfers, and therefore never calls USBDeferStatusStage(), then the
              application firmware should not call USBCtrlEPAllowStatusStage().
  
    Description:
  
    Conditions:
      None
  
    Input:
  
    Return:
  
    Remarks:
      None
    *****************************************************************************/
  void USBCtrlEPAllowStatusStage(void)
  {
      //Check and set two flags, prior to actually modifying any BDT entries.
      //This double checking is necessary to make certain that 
      //USBCtrlEPAllowStatusStage() can be called twice simultaneously (ex: once 
      //in main loop context, while simultaneously getting an interrupt which 
      //tries to call USBCtrlEPAllowStatusStage() again, at the same time).
      if(USBStatusStageEnabledFlag1 == false)
      {
          USBStatusStageEnabledFlag1 = true;
          if(USBStatusStageEnabledFlag2 == false)
          {
              USBStatusStageEnabledFlag2 = true;
          
              //Determine which endpoints (EP0 IN or OUT needs arming for the status
              //stage), based on the type of control transfer currently pending.
              if(controlTransferState == CTRL_TRF_RX)
              {
                  pBDTEntryIn[0]->CNT = 0;
                  pBDTEntryIn[0]->STAT.Val = _DAT1|(_DTSEN & _DTS_CHECKING_ENABLED);        
                  pBDTEntryIn[0]->STAT.Val |= _USIE;
              }
              else if(controlTransferState == CTRL_TRF_TX)
              {
                  BothEP0OutUOWNsSet = false;	//Indicator flag used in USBCtrlTrfOutHandler()
  
                  //This buffer (when ping pong buffering is enabled on EP0 OUT) receives the
                  //next SETUP packet.
                  #if((USB_PING_PONG_MODE == USB_PING_PONG__EP0_OUT_ONLY) || (USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG))
                      pBDTEntryEP0OutCurrent->CNT = USB_EP0_BUFF_SIZE;
                      pBDTEntryEP0OutCurrent->ADR = ConvertToPhysicalAddress(&SetupPkt);
                      pBDTEntryEP0OutCurrent->STAT.Val = _BSTALL; //Prepare endpoint to accept a SETUP transaction
                      pBDTEntryEP0OutCurrent->STAT.Val |= _USIE;
                      BothEP0OutUOWNsSet = true;	//Indicator flag used in USBCtrlTrfOutHandler()
                  #endif
  
                  //This EP0 OUT buffer receives the 0-byte OUT status stage packet.
                  pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
                  pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&SetupPkt);
                  pBDTEntryEP0OutNext->STAT.Val = _USIE;           // Note: DTSEN is 0
              }
          }    
      }
  }   
  
  
  /*******************************************************************************
    Function: void USBCtrlEPAllowDataStage(void);
      
    Summary: This function allows the data stage of either a host-to-device or
              device-to-host control transfer (with data stage) to complete.
              This function is meant to be used in conjunction with either the
              USBDeferOUTDataStage() or USBDeferINDataStage().  If the firmware
              does not call either USBDeferOUTDataStage() or USBDeferINDataStage(),
              then the firmware does not need to manually call 
              USBCtrlEPAllowDataStage(), as the USB stack will call this function
              instead.
       
    Description:
      
    Conditions: A control transfer (with data stage) should already be pending, 
                  if the firmware calls this function.  Additionally, the firmware
                  should have called either USBDeferOUTDataStage() or 
                  USBDeferINDataStage() at the start of the control transfer, if
                  the firmware will be calling this function manually.
  
    Input:
  
    Return:
  
    Remarks: 
    *****************************************************************************/
  void USBCtrlEPAllowDataStage(void)
  {
      USBDeferINDataStagePackets = false;
      USBDeferOUTDataStagePackets = false;
  
      if(controlTransferState == CTRL_TRF_RX) //(<setup><out><out>...<out><in>)
      {
          //Prepare EP0 OUT to receive the first OUT data packet in the data stage sequence.
          pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
          pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&CtrlTrfData);
          pBDTEntryEP0OutNext->STAT.Val = _DAT1|(_DTSEN & _DTS_CHECKING_ENABLED);
          pBDTEntryEP0OutNext->STAT.Val |= _USIE;
      }   
      else    //else must be controlTransferState == CTRL_TRF_TX (<setup><in><in>...<in><out>)
      {
          //Error check the data stage byte count.  Make sure the user specified
          //value was no greater than the number of bytes the host requested.
  		if(SetupPkt.wLength < inPipes[0].wCount.Val)
  		{
  			inPipes[0].wCount.Val = SetupPkt.wLength;
  		}
  		USBCtrlTrfTxService();  //Copies one IN data packet worth of data from application buffer
  		                        //to CtrlTrfData buffer.  Also keeps track of how many bytes remaining.
  
  	    //Cnt should have been initialized by responsible request owner (ex: by
  	    //using the USBEP0SendRAMPtr() or USBEP0SendROMPtr() API function).
  		pBDTEntryIn[0]->ADR = ConvertToPhysicalAddress(&CtrlTrfData);
  		pBDTEntryIn[0]->STAT.Val = _DAT1|(_DTSEN & _DTS_CHECKING_ENABLED);
          pBDTEntryIn[0]->STAT.Val |= _USIE;
      }     
  }    
  
  
  /******************************************************************************/
  /** Internal Functions *********************************************************/
  /******************************************************************************/
  
  /********************************************************************
   * Function:        void USBConfigureEndpoint(uint8_t EPNum, uint8_t direction)
   *
   * PreCondition:    None
   *
   * Input:           uint8_t EPNum - the endpoint to be configured
   *                  uint8_t direction - the direction to be configured
   *                                   (either OUT_FROM_HOST or IN_TO_HOST)
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This function will configure the specified 
   *                  endpoint
   *
   * Note:            None
   *******************************************************************/
  static void USBConfigureEndpoint(uint8_t EPNum, uint8_t direction)
  {
      volatile BDT_ENTRY* handle;
  
      //Compute a pointer to the even BDT entry corresponding to the
      //EPNum and direction values passed to this function.
      handle = (volatile BDT_ENTRY*)&BDT[EP0_OUT_EVEN]; //Get address of start of BDT
      handle += EP(EPNum,direction,0u);     //Add in offset to the BDT of interest
      
      handle->STAT.UOWN = 0;  //mostly redundant, since USBStdSetCfgHandler() 
      //already cleared the entire BDT table
  
      //Make sure our pBDTEntryIn/Out[] pointer is initialized.  Needed later
      //for USBTransferOnePacket() API calls.
      if(direction == OUT_FROM_HOST)
      {
          pBDTEntryOut[EPNum] = handle;
      }
      else
      {
          pBDTEntryIn[EPNum] = handle;
      }
  
      #if (USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG)
          handle->STAT.DTS = 0;
          (handle+1)->STAT.DTS = 1;
      #elif (USB_PING_PONG_MODE == USB_PING_PONG__NO_PING_PONG)
          //Set DTS to one because the first thing we will do
          //when transmitting is toggle the bit
          handle->STAT.DTS = 1;
      #elif (USB_PING_PONG_MODE == USB_PING_PONG__EP0_OUT_ONLY)
          if(EPNum != 0)
          {
              handle->STAT.DTS = 1;
          }
      #elif (USB_PING_PONG_MODE == USB_PING_PONG__ALL_BUT_EP0)    
          if(EPNum != 0)
          {
              handle->STAT.DTS = 0;
              (handle+1)->STAT.DTS = 1;
          }
      #endif
  }
  
  
  /******************************************************************************
   * Function:        void USBCtrlEPServiceComplete(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine wrap up the remaining tasks in servicing
   *                  a Setup Request. Its main task is to set the endpoint
   *                  controls appropriately for a given situation. See code
   *                  below.
   *                  There are three main scenarios:
   *                  a) There was no handler for the Request, in this case
   *                     a STALL should be sent out.
   *                  b) The host has requested a read control transfer,
   *                     endpoints are required to be setup in a specific way.
   *                  c) The host has requested a write control transfer, or
   *                     a control data stage is not required, endpoints are
   *                     required to be setup in a specific way.
   *
   *                  Packet processing is resumed by clearing PKTDIS bit.
   *
   * Note:            None
   *****************************************************************************/
  static void USBCtrlEPServiceComplete(void)
  {
      /*
       * PKTDIS bit is set when a Setup Transaction is received.
       * Clear to resume packet processing.
       */
      USBPacketDisable = 0;
  
  	//Check the busy bits and the SetupPtk.DataDir variables to determine what type of
  	//control transfer is currently in progress.  We need to know the type of control
  	//transfer that is currently pending, in order to know how to properly arm the 
  	//EP0 IN and EP0 OUT endpoints.
      if(inPipes[0].info.bits.busy == 0)
      {
          if(outPipes[0].info.bits.busy == 1)
          {
              controlTransferState = CTRL_TRF_RX;
              /*
               * Control Write:
               * <SETUP[0]><OUT[1]><OUT[0]>...<IN[1]> | <SETUP[0]>
               */
  
              //1. Prepare OUT EP to receive data, unless a USB class request handler
              //   function decided to defer the data stage (ex: because the intended
              //   RAM buffer wasn't available yet) by calling USBDeferDataStage().
              //   If it did so, it is then responsible for calling USBCtrlEPAllowDataStage(),
              //   once it is ready to begin receiving the data.
              if(USBDeferOUTDataStagePackets == false)
              {
                  USBCtrlEPAllowDataStage();
              }
              
              //2.  IN endpoint 0 status stage will be armed by USBCtrlEPAllowStatusStage() 
              //after all of the OUT data has been received and consumed, or if a timeout occurs.
              USBStatusStageEnabledFlag2 = false;
              USBStatusStageEnabledFlag1 = false;
          }
          else
          {
              /*
               * If no one knows how to service this request then stall.
               * Must also prepare EP0 to receive the next SETUP transaction.
               */
              pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
              pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&SetupPkt);
              pBDTEntryEP0OutNext->STAT.Val = _DAT0|(_DTSEN & _DTS_CHECKING_ENABLED)|_BSTALL;
              pBDTEntryEP0OutNext->STAT.Val |= _USIE;
              pBDTEntryIn[0]->STAT.Val = _BSTALL;
              pBDTEntryIn[0]->STAT.Val |= _USIE;
          }
      }
      else    // A module has claimed ownership of the control transfer session.
      {
  		if(SetupPkt.DataDir == USB_SETUP_DEVICE_TO_HOST_BITFIELD)
  		{
  			controlTransferState = CTRL_TRF_TX;
  			/*
  			 * Control Read:
  			 * <SETUP[0]><IN[1]><IN[0]>...<OUT[1]> | <SETUP[0]>
  			 *
  			 * 1. Prepare IN EP to transfer data to the host.  If however the data
  			 *    wasn't ready yet (ex: because the firmware needs to go and read it from
  			 *    some slow/currently unavailable resource, such as an external I2C EEPconst),
  			 *    Then the class request handler reponsible should call the USBDeferDataStage()
  			 *    macro.  In this case, the firmware may wait up to 500ms, before it is required
  			 *    to transmit the first IN data packet.  Once the data is ready, and the firmware
  			 *    is ready to begin sending the data, it should then call the 
  			 *    USBCtrlEPAllowDataStage() function to start the data stage.
  			 */
  			if(USBDeferINDataStagePackets == false)
              {
                  USBCtrlEPAllowDataStage();
  			}
  
              // 2. (Optionally) allow the status stage now, to prepare for early termination.
              //    Note: If a class request handler decided to set USBDeferStatusStagePacket == true,
              //    then it is responsible for eventually calling USBCtrlEPAllowStatusStage() once it
              //    is ready.  If the class request handler does this, it needs to be careful to
              //    be written so that it can handle the early termination scenario.
              //    Ex: It should call USBCtrlEPAllowStatusStage() when any of the following occurs:
              //    1.  The desired total number of bytes were sent to the host.
              //    2.  The number of bytes that the host originally requested (in the SETUP packet that 
              //        started the control transfer) has been reached.
              //    3.  Or, if a timeout occurs (ex: <50ms since the last successful EP0 IN transaction), regardless 
              //        of how many bytes have actually been sent.  This is necessary to prevent a deadlock situation
              //        (where the control transfer can't complete, due to continuous NAK on status stage) if the
              //        host performs early termination.  If enabled, the USB_ENABLE_STATUS_STAGE_TIMEOUTS usb_config.h
              //        option can take care of this for you.
              //    Note: For this type of control transfer, there is normally no harm in simply arming the
              //    status stage packet right now, even if the IN data is not ready yet.  This allows for
              //    immediate early termination, without adding unecessary delay.  Therefore, it is generally not
              //    recommended for the USB class handler firmware to call USBDeferStatusStage(), for this 
              //    type of control transfer.  If the USB class handler firmware needs more time to fetch the IN
              //    data that needs to be sent to the host, it should instead use the USBDeferDataStage() function.
              USBStatusStageEnabledFlag2 = false;
              USBStatusStageEnabledFlag1 = false;
              if(USBDeferStatusStagePacket == false)
              {
                  USBCtrlEPAllowStatusStage();
              } 
  		}
  		else   // (SetupPkt.DataDir == USB_SETUP_DIRECTION_HOST_TO_DEVICE)
  		{
  			//This situation occurs for special types of control transfers,
  			//such as that which occurs when the host sends a SET_ADDRESS
  			//control transfer.  Ex:
  			//
  			//<SETUP[0]><IN[1]> | <SETUP[0]>
  				
  			//Although the data direction is HOST_TO_DEVICE, there is no data stage
  			//(hence: outPipes[0].info.bits.busy == 0).  There is however still
  			//an IN status stage.
  
  			controlTransferState = CTRL_TRF_RX;     //Since this is a HOST_TO_DEVICE control transfer
  			
  			//1. Prepare OUT EP to receive the next SETUP packet.
  			pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
  			pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&SetupPkt);
  			pBDTEntryEP0OutNext->STAT.Val = _BSTALL;
              pBDTEntryEP0OutNext->STAT.Val |= _USIE;
  				
  			//2. Prepare for IN status stage of the control transfer
              USBStatusStageEnabledFlag2 = false;
              USBStatusStageEnabledFlag1 = false;
  			if(USBDeferStatusStagePacket == false)
              {
                  USBCtrlEPAllowStatusStage();
              } 
  		}
  
      }//end if(ctrl_trf_session_owner == MUID_NULL)
  
  }//end USBCtrlEPServiceComplete
  
  
  /******************************************************************************
   * Function:        void USBCtrlTrfTxService(void)
   *
   * PreCondition:    pSrc, wCount, and usb_stat.ctrl_trf_mem are setup properly.
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine is used for device to host control transfers 
   *					(IN transactions).  This function takes care of managing a
   *                  transfer over multiple USB transactions.
   *					This routine should be called from only two places.
   *                  One from USBCtrlEPServiceComplete() and one from
   *                  USBCtrlTrfInHandler().
   *
   * Note:            
   *****************************************************************************/
  static void USBCtrlTrfTxService(void)
  {
      uint8_t byteToSend;
  
      //Figure out how many bytes of data to send in the next IN transaction.
      //Assume a full size packet, unless otherwise determined below.
      byteToSend = USB_EP0_BUFF_SIZE;         
      if(inPipes[0].wCount.Val < (uint8_t)USB_EP0_BUFF_SIZE)
      {
          byteToSend = inPipes[0].wCount.Val;
  
          //Keep track of whether or not we have sent a "short packet" yet.
          //This is useful so that later on, we can configure EP0 IN to STALL,
          //after we have sent all of the intended data.  This makes sure the
          //hardware STALLs if the host erroneously tries to send more IN token 
          //packets, requesting more data than intended in the control transfer.
          if(shortPacketStatus == SHORT_PKT_NOT_USED)
          {
              shortPacketStatus = SHORT_PKT_PENDING;
          }
          else if(shortPacketStatus == SHORT_PKT_PENDING)
          {
              shortPacketStatus = SHORT_PKT_SENT;
          }
      }
  
      //Keep track of how many bytes remain to be sent in the transfer, by
      //subtracting the number of bytes about to be sent from the total.
      inPipes[0].wCount.Val -= byteToSend;
      
      //Next, load the number of bytes to send to BC7..0 in buffer descriptor.
      //Note: Control endpoints may never have a max packet size of > 64 bytes.
      //Therefore, the BC8 and BC9 bits should always be maintained clear.
      pBDTEntryIn[0]->CNT = byteToSend;
  
      //Now copy the data from the source location, to the CtrlTrfData[] buffer,
      //which we will send to the host.
      pDst = (USB_VOLATILE uint8_t*)CtrlTrfData;                // Set destination pointer
      if(inPipes[0].info.bits.ctrl_trf_mem == USB_EP0_ROM)   // Determine type of memory source
      {
          while(byteToSend)
          {
              *pDst++ = *inPipes[0].pSrc.bRom++;
              byteToSend--;
          }//end while(byte_to_send.Val)
      }
      else  // RAM
      {
          while(byteToSend)
          {
              *pDst++ = *inPipes[0].pSrc.bRam++;
              byteToSend--;
          }//end while(byte_to_send.Val)
      }//end if(usb_stat.ctrl_trf_mem == _const)
  }//end USBCtrlTrfTxService
  
  /******************************************************************************
   * Function:        void USBCtrlTrfRxService(void)
   *
   * PreCondition:    pDst and wCount are setup properly.
   *                  pSrc is always &CtrlTrfData
   *                  usb_stat.ctrl_trf_mem is always USB_EP0_RAM.
   *                  wCount should be set to 0 at the start of each control
   *                  transfer.
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine is used for host to device control transfers
   *					(uses OUT transactions).  This function receives the data that arrives
   *					on EP0 OUT, and copies it into the appropriate outPipes[0].pDst.bRam
   *					buffer.  Once the host has sent all the data it was intending
   *					to send, this function will call the appropriate outPipes[0].pFunc()
   *					handler (unless it is NULL), so that it can be used by the
   *					intended target firmware.
   *
   * Note:            None
   *****************************************************************************/
  static void USBCtrlTrfRxService(void)
  {
      uint8_t byteToRead;
      uint8_t i;
  
      //Load byteToRead with the number of bytes the host just sent us in the 
      //last OUT transaction.
      byteToRead = pBDTEntryEP0OutCurrent->CNT;   
  
      //Update the "outPipes[0].wCount.Val", which keeps track of the total number
      //of remaining bytes expected to be received from the host, in the control
      //transfer.  First check to see if the host sent us more bytes than the
      //application firmware was expecting to receive.
      if(byteToRead > outPipes[0].wCount.Val)
      {
          byteToRead = outPipes[0].wCount.Val;
      }	
      //Reduce the number of remaining bytes by the number we just received.
      outPipes[0].wCount.Val -= byteToRead;
  
      //Copy the OUT DATAx packet bytes that we just received from the host,
      //into the user application buffer space.
      for(i=0;i<byteToRead;i++)
      {
          *outPipes[0].pDst.bRam++ = CtrlTrfData[i];
      }//end while(byteToRead.Val)
  
      //If there is more data to receive, prepare EP0 OUT so that it can receive 
  	//the next packet in the sequence.
      if(outPipes[0].wCount.Val > 0)
      {
          pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
          pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&CtrlTrfData);
          if(pBDTEntryEP0OutCurrent->STAT.DTS == 0)
          {
              pBDTEntryEP0OutNext->STAT.Val = _DAT1|(_DTSEN & _DTS_CHECKING_ENABLED);
              pBDTEntryEP0OutNext->STAT.Val |= _USIE;
          }
          else
          {
              pBDTEntryEP0OutNext->STAT.Val = _DAT0|(_DTSEN & _DTS_CHECKING_ENABLED);
              pBDTEntryEP0OutNext->STAT.Val |= _USIE;
          }
      }
      else
      {
  	    //We have received all OUT packets that we were expecting to
  	    //receive for the control transfer.  Prepare EP0 OUT to receive
  		//the next SETUP transaction that may arrive.
          pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
          pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&SetupPkt);
          //Configure EP0 OUT to receive the next SETUP transaction for any future
          //control transfers.  However, set BSTALL in case the host tries to send
          //more data than it claims it was going to send.
          pBDTEntryEP0OutNext->STAT.Val = _BSTALL;
          pBDTEntryEP0OutNext->STAT.Val |= _USIE;
  
  		//All data bytes for the host to device control write (OUT) have now been
  		//received successfully.
  		//Go ahead and call the user specified callback function, to use/consume
  		//the control transfer data (ex: if the "void (*function)" parameter 
  		//was non-NULL when USBEP0Receive() was called).
          if(outPipes[0].pFunc != NULL)
          {
              #if defined(__XC8)
                  //Special pragmas to suppress an expected/harmless warning
                  //message when building with the XC8 compiler
                  #pragma warning push
                  #pragma warning disable 1471
                  outPipes[0].pFunc();    //Call the user's callback function
                  #pragma warning pop
              #else
                  outPipes[0].pFunc();    //Call the user's callback function
              #endif
          }
          outPipes[0].info.bits.busy = 0;    
  
          //Ready to arm status stage IN transaction now, if the application
          //firmware has completed processing the request.  If it is still busy
          //and needs more time to finish handling the request, then the user
          //callback (the one called by the outPipes[0].pFunc();) should set the
          //USBDeferStatusStagePacket to true (by calling USBDeferStatusStage()).  In
          //this case, it is the application's firmware responsibility to call 
          //the USBCtrlEPAllowStatusStage() function, once it is fully done handling the request.
          //Note: The application firmware must process the request and call
          //USBCtrlEPAllowStatusStage() in a semi-timely fashion.  "Semi-timely"
          //means either 50ms, 500ms, or 5 seconds, depending on the type of
          //control transfer.  See the USB 2.0 specification section 9.2.6 for
          //more details.
          if(USBDeferStatusStagePacket == false)
          {
              USBCtrlEPAllowStatusStage();
          }            
      }    
  
  }//end USBCtrlTrfRxService
  
  
  /********************************************************************
   * Function:        void USBStdSetCfgHandler(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine first disables all endpoints by
   *                  clearing UEP registers. It then configures
   *                  (initializes) endpoints by calling the callback
   *                  function USBCBInitEP().
   *
   * Note:            None
   *******************************************************************/
  static void USBStdSetCfgHandler(void)
  {
      uint8_t i;
  
      // This will generate a zero length packet
      inPipes[0].info.bits.busy = 1;            
  
      //Clear all of the endpoint control registers
      DisableNonZeroEndpoints(USB_MAX_EP_NUMBER);
  
      //Clear all of the BDT entries
      memset((void*)&BDT[0], 0x00, sizeof(BDT));
  
      // Assert reset request to all of the Ping Pong buffer pointers
      USBPingPongBufferReset = 1;                                   
  
  	//Re-Initialize all ping pong software state bits to 0 (which corresponds to
  	//the EVEN buffer being the next one that will be used), since we are also 
  	//doing a hardware ping pong pointer reset above.
  	for(i = 0; i < (uint8_t)(USB_MAX_EP_NUMBER+1u); i++)
  	{
  		ep_data_in[i].Val = 0u;
          ep_data_out[i].Val = 0u;
  	}
  
      //clear the alternate interface settings
      memset((void*)&USBAlternateInterface,0x00,USB_MAX_NUM_INT);
  
      //Stop trying to reset ping pong buffer pointers
      USBPingPongBufferReset = 0;
  
      pBDTEntryIn[0] = (volatile BDT_ENTRY*)&BDT[EP0_IN_EVEN];
  
  	//Set the next out to the current out packet
      pBDTEntryEP0OutCurrent = (volatile BDT_ENTRY*)&BDT[EP0_OUT_EVEN];
      pBDTEntryEP0OutNext = pBDTEntryEP0OutCurrent;
  
      //set the current configuration
      USBActiveConfiguration = SetupPkt.bConfigurationValue;
  
      //if the configuration value == 0
      if(USBActiveConfiguration == 0)
      {
          //Go back to the addressed state
          USBDeviceState = ADDRESS_STATE;
      }
      else
      {
          //initialize the required endpoints
          USB_SET_CONFIGURATION_HANDLER(EVENT_CONFIGURED,(void*)&USBActiveConfiguration,1);
  
          //Otherwise go to the configured state.  Update the state variable last,
          //after performing all of the set configuration related initialization
          //tasks.
          USBDeviceState = CONFIGURED_STATE;		
      }//end if(SetupPkt.bConfigurationValue == 0)
  }//end USBStdSetCfgHandler
  
  
  /********************************************************************
   * Function:        void USBStdGetDscHandler(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine handles the standard GET_DESCRIPTOR
   *                  request.
   *
   * Note:            None
   *******************************************************************/
  static void USBStdGetDscHandler(void)
  {
      if(SetupPkt.bmRequestType == 0x80)
      {
          inPipes[0].info.Val = USB_EP0_ROM | USB_EP0_BUSY | USB_EP0_INCLUDE_ZERO;
  
          switch(SetupPkt.bDescriptorType)
          {
              case USB_DESCRIPTOR_DEVICE:
                  #if !defined(USB_USER_DEVICE_DESCRIPTOR)
                      inPipes[0].pSrc.bRom = (const uint8_t*)&device_dsc;
                  #else
                      inPipes[0].pSrc.bRom = (const uint8_t*)USB_USER_DEVICE_DESCRIPTOR;
                  #endif
                  inPipes[0].wCount.Val = sizeof(device_dsc);
                  break;
              case USB_DESCRIPTOR_CONFIGURATION:
                  //First perform error case check, to make sure the host is requesting a 
                  //legal descriptor index.  If the request index is illegal, don't do 
                  //anything (so that the default STALL response will be sent).
                  if(SetupPkt.bDscIndex < USB_MAX_NUM_CONFIG_DSC)
                  {
                      #if !defined(USB_USER_CONFIG_DESCRIPTOR)
                          inPipes[0].pSrc.bRom = *(USB_CD_Ptr+SetupPkt.bDscIndex);
                      #else
                          inPipes[0].pSrc.bRom = *(USB_USER_CONFIG_DESCRIPTOR+SetupPkt.bDscIndex);
                      #endif
  
                      //This must be loaded using byte addressing.  The source pointer
                      //  may not be word aligned for the 16 or 32 bit machines resulting
                      //  in an address error on the dereference.
                      inPipes[0].wCount.byte.LB = *(inPipes[0].pSrc.bRom+2);
                      inPipes[0].wCount.byte.HB = *(inPipes[0].pSrc.bRom+3);
                  }
  				else
  				{
  					inPipes[0].info.Val = 0;
  				}
                  break;
              case USB_DESCRIPTOR_STRING:
                  //USB_NUM_STRING_DESCRIPTORS was introduced as optional in release v2.3.  In v2.4 and
                  //  later it is now manditory.  This should be defined in usb_config.h and should
                  //  indicate the number of string descriptors.
                  if(SetupPkt.bDscIndex<USB_NUM_STRING_DESCRIPTORS)
                  {
                      //Get a pointer to the String descriptor requested
                      inPipes[0].pSrc.bRom = *(USB_SD_Ptr+SetupPkt.bDscIndex);
                      // Set data count
                      inPipes[0].wCount.Val = *inPipes[0].pSrc.bRom;                    
                  }
                  #if defined(IMPLEMENT_MICROSOFT_OS_DESCRIPTOR)
                  else if(SetupPkt.bDscIndex == MICROSOFT_OS_DESCRIPTOR_INDEX)
                  {
                      //Get a pointer to the special MS OS string descriptor requested
                      inPipes[0].pSrc.bRom = (const uint8_t*)&MSOSDescriptor;
                      // Set data count
                      inPipes[0].wCount.Val = *inPipes[0].pSrc.bRom;                    
                  }    
                  #endif
                  else
                  {
                      inPipes[0].info.Val = 0;
                  }
                  break;
              default:
                  inPipes[0].info.Val = 0;
                  break;
          }//end switch
      }//end if
  }//end USBStdGetDscHandler
  
  /********************************************************************
   * Function:        void USBStdGetStatusHandler(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine handles the standard GET_STATUS request
   *
   * Note:            None
   *******************************************************************/
  static void USBStdGetStatusHandler(void)
  {
      CtrlTrfData[0] = 0;                 // Initialize content
      CtrlTrfData[1] = 0;
  
      switch(SetupPkt.Recipient)
      {
          case USB_SETUP_RECIPIENT_DEVICE_BITFIELD:
              inPipes[0].info.bits.busy = 1;
              /*
               * [0]: bit0: Self-Powered Status [0] Bus-Powered [1] Self-Powered
               *      bit1: RemoteWakeup        [0] Disabled    [1] Enabled
               */
              if(self_power == 1) // self_power is defined in HardwareProfile.h
              {
                  CtrlTrfData[0]|=0x01;
              }
  
              if(RemoteWakeup == true)
              {
                  CtrlTrfData[0]|=0x02;
              }
              break;
          case USB_SETUP_RECIPIENT_INTERFACE_BITFIELD:
              inPipes[0].info.bits.busy = 1;     // No data to update
              break;
          case USB_SETUP_RECIPIENT_ENDPOINT_BITFIELD:
              inPipes[0].info.bits.busy = 1;
              /*
               * [0]: bit0: Halt Status [0] Not Halted [1] Halted
               */
              {
                  BDT_ENTRY *p;
  
                  if(SetupPkt.EPDir == 0)
                  {
                      p = (BDT_ENTRY*)pBDTEntryOut[SetupPkt.EPNum];
                  }
                  else
                  {
                      p = (BDT_ENTRY*)pBDTEntryIn[SetupPkt.EPNum];
                  }
  
                  if((p->STAT.UOWN == 1) && (p->STAT.BSTALL == 1))
                      CtrlTrfData[0]=0x01;    // Set bit0
                  break;
              }
      }//end switch
  
      if(inPipes[0].info.bits.busy == 1)
      {
          inPipes[0].pSrc.bRam = (uint8_t*)&CtrlTrfData;        // Set Source
          inPipes[0].info.bits.ctrl_trf_mem = USB_EP0_RAM;      // Set memory type
          inPipes[0].wCount.v[0] = 2;                           // Set data count
      }//end if(...)
  }//end USBStdGetStatusHandler
  
  /********************************************************************
   * Function:        void USBStallHandler(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    
   *
   * Overview:        This function handles the event of a STALL 
   *                  occuring on the bus
   *
   * Note:            None
   *******************************************************************/
  static void USBStallHandler(void)
  {
      /*
       * Does not really have to do anything here,
       * even for the control endpoint.
       * All BDs of Endpoint 0 are owned by SIE right now,
       * but once a Setup Transaction is received, the ownership
       * for EP0_OUT will be returned to CPU.
       * When the Setup Transaction is serviced, the ownership
       * for EP0_IN will then be forced back to CPU by firmware.
       */
  
      if(U1EP0bits.EPSTALL == 1)
      {
          // UOWN - if 0, owned by CPU, if 1, owned by SIE
          if((pBDTEntryEP0OutCurrent->STAT.Val == _USIE) && (pBDTEntryIn[0]->STAT.Val == (_USIE|_BSTALL)))
          {
              // Set ep0Bo to stall also
              pBDTEntryEP0OutCurrent->STAT.Val = _DAT0|(_DTSEN & _DTS_CHECKING_ENABLED)|_BSTALL;
              pBDTEntryEP0OutCurrent->STAT.Val |= _USIE;
          }//end if
          U1EP0bits.EPSTALL = 0;               // Clear stall status
      }//end if
  
      USBClearInterruptFlag(USBStallIFReg,USBStallIFBitNum);
  }
  
  /********************************************************************
   * Function:        void USBSuspend(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    
   *
   * Overview:        This function handles if the host tries to 
   *                  suspend the device
   *
   * Note:            None
   *******************************************************************/
  static void USBSuspend(void)
  {
      /*
       * NOTE: Do not clear UIRbits.ACTVIF here!
       * Reason:
       * ACTVIF is only generated once an IDLEIF has been generated.
       * This is a 1:1 ratio interrupt generation.
       * For every IDLEIF, there will be only one ACTVIF regardless of
       * the number of subsequent bus transitions.
       *
       * If the ACTIF is cleared here, a problem could occur when:
       * [       IDLE       ][bus activity ->
       * <--- 3 ms ----->     ^
       *                ^     ACTVIF=1
       *                IDLEIF=1
       *  #           #           #           #   (#=Program polling flags)
       *                          ^
       *                          This polling loop will see both
       *                          IDLEIF=1 and ACTVIF=1.
       *                          However, the program services IDLEIF first
       *                          because ACTIVIE=0.
       *                          If this routine clears the only ACTIVIF,
       *                          then it can never get out of the suspend
       *                          mode.
       */
      USBActivityIE = 1;                     // Enable bus activity interrupt
      USBClearInterruptFlag(USBIdleIFReg,USBIdleIFBitNum);
  
      #if defined(__18CXX) || defined(_PIC14E) || defined(__XC8)
          U1CONbits.SUSPND = 1;                   // Put USB module in power conserve
                                                  // mode, SIE clock inactive
      #endif
      USBBusIsSuspended = true;
   
      /*
       * At this point the PIC can go into sleep,idle, or
       * switch to a slower clock, etc.  This should be done in the
       * USBCBSuspend() if necessary.
       */
      USB_SUSPEND_HANDLER(EVENT_SUSPEND,0,0);
  }
  
  /********************************************************************
   * Function:        void USBWakeFromSuspend(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:
   *
   * Note:            None
   *******************************************************************/
  static void USBWakeFromSuspend(void)
  {
      USBBusIsSuspended = false;
  
      /*
       * If using clock switching, the place to restore the original
       * microcontroller core clock frequency is in the USBCBWakeFromSuspend() callback
       */
      USB_WAKEUP_FROM_SUSPEND_HANDLER(EVENT_RESUME,0,0);
  
      #if defined(__18CXX) || defined(_PIC14E) || defined(__XC8)
          //To avoid improperly clocking the USB module, make sure the oscillator
          //settings are consistant with USB operation before clearing the SUSPND bit.
          //Make sure the correct oscillator settings are selected in the 
          //"USB_WAKEUP_FROM_SUSPEND_HANDLER(EVENT_RESUME,0,0)" handler.
          U1CONbits.SUSPND = 0;   // Bring USB module out of power conserve
                                  // mode.
      #endif
  
  
      USBActivityIE = 0;
  
      /********************************************************************
      Bug Fix: Feb 26, 2007 v2.1
      *********************************************************************
      The ACTVIF bit cannot be cleared immediately after the USB module wakes
      up from Suspend or while the USB module is suspended. A few clock cycles
      are required to synchronize the internal hardware state machine before
      the ACTIVIF bit can be cleared by firmware. Clearing the ACTVIF bit
      before the internal hardware is synchronized may not have an effect on
      the value of ACTVIF. Additonally, if the USB module uses the clock from
      the 96 MHz PLL source, then after clearing the SUSPND bit, the USB
      module may not be immediately operational while waiting for the 96 MHz
      PLL to lock.
      ********************************************************************/
  
      // UIRbits.ACTVIF = 0;                      // Removed
      #if defined(__18CXX) || defined(__XC8)
      while(USBActivityIF)
      #endif
      {
          USBClearInterruptFlag(USBActivityIFReg,USBActivityIFBitNum);
      }  // Added
  
  }//end USBWakeFromSuspend
  
  /********************************************************************
   * Function:        void USBCtrlEPService(void)
   *
   * PreCondition:    USTAT is loaded with a valid endpoint address.
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        USBCtrlEPService checks for three transaction
   *                  types that it knows how to service and services
   *                  them:
   *                  1. EP0 SETUP
   *                  2. EP0 OUT
   *                  3. EP0 IN
   *                  It ignores all other types (i.e. EP1, EP2, etc.)
   *
   * Note:            None
   *******************************************************************/
  static void USBCtrlEPService(void)
  {
      //If we get to here, that means a successful transaction has just occurred 
      //on EP0.  This means "progress" has occurred in the currently pending 
      //control transfer, so we should re-initialize our timeout counter.
      #if defined(USB_ENABLE_STATUS_STAGE_TIMEOUTS)
          USBStatusStageTimeoutCounter = USB_STATUS_STAGE_TIMEOUT;
      #endif
  	
  	//Check if the last transaction was on EP0 OUT endpoint (of any kind, to either the even or odd buffer if ping pong buffers used)
      if((USTATcopy.Val & USTAT_EP0_PP_MASK) == USTAT_EP0_OUT_EVEN)
      {
  		//Point to the EP0 OUT buffer of the buffer that arrived
          #if defined (_PIC14E) || defined(__18CXX) || defined(__XC8)
              pBDTEntryEP0OutCurrent = (volatile BDT_ENTRY*)&BDT[(USTATcopy.Val & USTAT_EP_MASK)>>1];
          #elif defined(__C30__) || defined(__C32__) || defined __XC16__
              pBDTEntryEP0OutCurrent = (volatile BDT_ENTRY*)&BDT[(USTATcopy.Val & USTAT_EP_MASK)>>2];
          #else
              #error "unimplemented"
          #endif
  
  		//Set the next out to the current out packet
          pBDTEntryEP0OutNext = pBDTEntryEP0OutCurrent;
  		//Toggle it to the next ping pong buffer (if applicable)
          ((uint8_t_VAL*)&pBDTEntryEP0OutNext)->Val ^= USB_NEXT_EP0_OUT_PING_PONG;
  
  		//If the current EP0 OUT buffer has a SETUP packet
          if(pBDTEntryEP0OutCurrent->STAT.PID == PID_SETUP)
          {
              unsigned char setup_cnt;
  
  	        //The SETUP transaction data may have gone into the the CtrlTrfData 
  	        //buffer, or elsewhere, depending upon how the BDT was prepared
  	        //before the transaction.  Therefore, we should copy the data to the 
  	        //SetupPkt buffer so it can be processed correctly by USBCtrlTrfSetupHandler().		    
              for(setup_cnt = 0; setup_cnt < 8u; setup_cnt++) //SETUP data packets always contain exactly 8 bytes.
              {
                  *(uint8_t*)((uint8_t*)&SetupPkt + setup_cnt) = *(uint8_t*)ConvertToVirtualAddress(pBDTEntryEP0OutCurrent->ADR);
                  pBDTEntryEP0OutCurrent->ADR++;
              }    
              pBDTEntryEP0OutCurrent->ADR = ConvertToPhysicalAddress(&SetupPkt);
  
  			//Handle the control transfer (parse the 8-byte SETUP command and figure out what to do)
              USBCtrlTrfSetupHandler();
          }
          else
          {
  			//Handle the DATA transfer
              USBCtrlTrfOutHandler();
          }
      }
      else if((USTATcopy.Val & USTAT_EP0_PP_MASK) == USTAT_EP0_IN)
      {
  		//Otherwise the transmission was and EP0 IN
  		//  so take care of the IN transfer
          USBCtrlTrfInHandler();
      }
  
  }//end USBCtrlEPService
  
  /********************************************************************
   * Function:        void USBCtrlTrfSetupHandler(void)
   *
   * PreCondition:    SetupPkt buffer is loaded with valid USB Setup Data
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine is a task dispatcher and has 3 stages.
   *                  1. It initializes the control transfer state machine.
   *                  2. It calls on each of the module that may know how to
   *                     service the Setup Request from the host.
   *                     Module Example: USBD, HID, CDC, MSD, ...
   *                     A callback function, USBCBCheckOtherReq(),
   *                     is required to call other module handlers.
   *                  3. Once each of the modules has had a chance to check if
   *                     it is responsible for servicing the request, stage 3
   *                     then checks direction of the transfer to determine how
   *                     to prepare EP0 for the control transfer.
   *                     Refer to USBCtrlEPServiceComplete() for more details.
   *
   * Note:            Microchip USB Firmware has three different states for
   *                  the control transfer state machine:
   *                  1. WAIT_SETUP
   *                  2. CTRL_TRF_TX (device sends data to host through IN transactions)
   *                  3. CTRL_TRF_RX (device receives data from host through OUT transactions)
   *                  Refer to firmware manual to find out how one state
   *                  is transitioned to another.
   *
   *                  A Control Transfer is composed of many USB transactions.
   *                  When transferring data over multiple transactions,
   *                  it is important to keep track of data source, data
   *                  destination, and data count. These three parameters are
   *                  stored in pSrc,pDst, and wCount. A flag is used to
   *                  note if the data source is from const or RAM.
   *
   *******************************************************************/
  static void USBCtrlTrfSetupHandler(void)
  {
      //--------------------------------------------------------------------------
      //1. Re-initialize state tracking variables related to control transfers.
      //--------------------------------------------------------------------------
      shortPacketStatus = SHORT_PKT_NOT_USED;  
      USBDeferStatusStagePacket = false;
      USBDeferINDataStagePackets = false;
      USBDeferOUTDataStagePackets = false;
      BothEP0OutUOWNsSet = false;
      controlTransferState = WAIT_SETUP;
  
      //Abandon any previous control transfers that might have been using EP0.
      //Ordinarily, nothing actually needs abandoning, since the previous control
      //transfer would have completed successfully prior to the host sending the next
      //SETUP packet.  However, in a timeout error case, or after an EP0 STALL event,
      //one or more UOWN bits might still be set.  If so, we should clear the UOWN bits,
      //so the EP0 IN/OUT endpoints are in a known inactive state, ready for re-arming
      //by the class request handler that will be called next.
      pBDTEntryIn[0]->STAT.Val &= ~(_USIE);     
      ((uint8_t_VAL*)&pBDTEntryIn[0])->Val ^= USB_NEXT_EP0_IN_PING_PONG;
      pBDTEntryIn[0]->STAT.Val &= ~(_USIE);      
      ((uint8_t_VAL*)&pBDTEntryIn[0])->Val ^= USB_NEXT_EP0_IN_PING_PONG;
      pBDTEntryEP0OutNext->STAT.Val &= ~(_USIE);         
  
      inPipes[0].info.Val = 0;
      inPipes[0].wCount.Val = 0;
      outPipes[0].info.Val = 0;
      outPipes[0].wCount.Val = 0;
      
  
      //--------------------------------------------------------------------------
      //2. Now find out what was in the SETUP packet, and begin handling the request.
      //--------------------------------------------------------------------------
      USBCheckStdRequest();                                               //Check for standard USB "Chapter 9" requests.
      USB_NONSTANDARD_EP0_REQUEST_HANDLER(EVENT_EP0_REQUEST,0,0); //Check for USB device class specific requests
  
  
      //--------------------------------------------------------------------------
      //3. Re-arm EP0 IN and EP0 OUT endpoints, based on the control transfer in 
      //   progress.  If one of the above handlers (in step 2) knew how to process
      //   the request, it will have set one of the inPipes[0].info.bits.busy or
      //   outPipes[0].info.bits.busy flags = 1.  This lets the
      //   USBCtrlEPServiceComplete() function know how and which endpoints to 
      //   arm.  If both info.bits.busy flags are = 0, then no one knew how to
      //   process the request.  In this case, the default behavior will be to
      //   perform protocol STALL on EP0.
      //-------------------------------------------------------------------------- 
      USBCtrlEPServiceComplete();
  }//end USBCtrlTrfSetupHandler
  
  
  /******************************************************************************
   * Function:        void USBCtrlTrfOutHandler(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine handles an OUT transaction according to
   *                  which control transfer state is currently active.
   *
   * Note:            Note that if the the control transfer was from
   *                  host to device, the session owner should be notified
   *                  at the end of each OUT transaction to service the
   *                  received data.
   *
   *****************************************************************************/
  static void USBCtrlTrfOutHandler(void)
  {
      if(controlTransferState == CTRL_TRF_RX)
      {
          USBCtrlTrfRxService();	//Copies the newly received data into the appropriate buffer and configures EP0 OUT for next transaction.
      }
      else //In this case the last OUT transaction must have been a status stage of a CTRL_TRF_TX (<setup><in><in>...<OUT>  <-- this last OUT just occurred as the status stage)
      {
          //If the status stage is complete, this means we are done with the 
          //control transfer.  Go back to the idle "WAIT_SETUP" state.
          controlTransferState = WAIT_SETUP;
  
          //Prepare EP0 OUT for the next SETUP transaction, however, it may have
          //already been prepared if ping-pong buffering was enabled on EP0 OUT,
          //and the last control transfer was of direction: device to host, see
          //USBCtrlEPServiceComplete().  If it was already prepared, do not want
          //to do anything to the BDT.
          if(BothEP0OutUOWNsSet == false)
          {
              pBDTEntryEP0OutNext->CNT = USB_EP0_BUFF_SIZE;
              pBDTEntryEP0OutNext->ADR = ConvertToPhysicalAddress(&SetupPkt);
              pBDTEntryEP0OutNext->STAT.Val = _DAT0|(_DTSEN & _DTS_CHECKING_ENABLED)|_BSTALL;
              pBDTEntryEP0OutNext->STAT.Val |= _USIE;
          }
          else
          {
                  BothEP0OutUOWNsSet = false;
          }
      }
  }
  
  /******************************************************************************
   * Function:        void USBCtrlTrfInHandler(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine handles an IN transaction according to
   *                  which control transfer state is currently active.
   *
   * Note:            A Set Address Request must not change the acutal address
   *                  of the device until the completion of the control
   *                  transfer. The end of the control transfer for Set Address
   *                  Request is an IN transaction. Therefore it is necessary
   *                  to service this unique situation when the condition is
   *                  right. Macro mUSBCheckAdrPendingState is defined in
   *                  usb9.h and its function is to specifically service this
   *                  event.
   *****************************************************************************/
  static void USBCtrlTrfInHandler(void)
  {
      uint8_t lastDTS;
  
      lastDTS = pBDTEntryIn[0]->STAT.DTS;
  
      //switch to the next ping pong buffer
      ((uint8_t_VAL*)&pBDTEntryIn[0])->Val ^= USB_NEXT_EP0_IN_PING_PONG;
  
      //Must check if in ADR_PENDING_STATE.  If so, we need to update the address
      //now, since the IN status stage of the (set address) control transfer has 
      //evidently completed successfully.
      if(USBDeviceState == ADR_PENDING_STATE)
      {
          U1ADDR = (SetupPkt.bDevADR & 0x7F);
          if(U1ADDR != 0u)
          {
              USBDeviceState=ADDRESS_STATE;
          }
          else
          {
              USBDeviceState=DEFAULT_STATE;
          }
      }//end if
  
  
      if(controlTransferState == CTRL_TRF_TX)
      {
          pBDTEntryIn[0]->ADR = ConvertToPhysicalAddress(CtrlTrfData);
          USBCtrlTrfTxService();
  
          //Check if we have already sent a short packet.  If so, configure
          //the endpoint to STALL in response to any further IN tokens (in the
          //case that the host erroneously tries to receive more data than it
          //should).
          if(shortPacketStatus == SHORT_PKT_SENT)
          {
              // If a short packet has been sent, don't want to send any more,
              // stall next time if host is still trying to read.
              pBDTEntryIn[0]->STAT.Val = _BSTALL;
              pBDTEntryIn[0]->STAT.Val |= _USIE;
          }
          else
          {
              if(lastDTS == 0)
              {
                  pBDTEntryIn[0]->STAT.Val = _DAT1|(_DTSEN & _DTS_CHECKING_ENABLED);
                  pBDTEntryIn[0]->STAT.Val |= _USIE;
              }
              else
              {
                  pBDTEntryIn[0]->STAT.Val = _DAT0|(_DTSEN & _DTS_CHECKING_ENABLED);
                  pBDTEntryIn[0]->STAT.Val |= _USIE;
              }
          }//end if(...)else
      }
  	else // must have been a CTRL_TRF_RX status stage IN packet (<setup><out><out>...<IN>  <-- this last IN just occurred as the status stage)
  	{
          //if someone is still expecting data from the control transfer
          //  then make sure to terminate that request and let them know that
          //  they are done
          if(outPipes[0].info.bits.busy == 1)
          {
              if(outPipes[0].pFunc != NULL)
              {
                  outPipes[0].pFunc();
              }
              outPipes[0].info.bits.busy = 0;
          }
      	
          controlTransferState = WAIT_SETUP;
          //Don't need to arm EP0 OUT here.  It was already armed by the last <out> that
          //got processed by the USBCtrlTrfRxService() handler.
  	}	
  
  }
  
  
  /********************************************************************
   * Function:        void USBCheckStdRequest(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          None
   *
   * Side Effects:    None
   *
   * Overview:        This routine checks the setup data packet to see
   *                  if it knows how to handle it
   *
   * Note:            None
   *******************************************************************/
  static void USBCheckStdRequest(void)
  {
      if(SetupPkt.RequestType != USB_SETUP_TYPE_STANDARD_BITFIELD) return;
  
      switch(SetupPkt.bRequest)
      {
          case USB_REQUEST_SET_ADDRESS:
              inPipes[0].info.bits.busy = 1;            // This will generate a zero length packet
              USBDeviceState = ADR_PENDING_STATE;       // Update state only
              /* See USBCtrlTrfInHandler() for the next step */
              break;
          case USB_REQUEST_GET_DESCRIPTOR:
              USBStdGetDscHandler();
              break;
          case USB_REQUEST_SET_CONFIGURATION:
              USBStdSetCfgHandler();
              break;
          case USB_REQUEST_GET_CONFIGURATION:
              inPipes[0].pSrc.bRam = (uint8_t*)&USBActiveConfiguration;         // Set Source
              inPipes[0].info.bits.ctrl_trf_mem = USB_EP0_RAM;               // Set memory type
              inPipes[0].wCount.v[0] = 1;                         // Set data count
              inPipes[0].info.bits.busy = 1;
              break;
          case USB_REQUEST_GET_STATUS:
              USBStdGetStatusHandler();
              break;
          case USB_REQUEST_CLEAR_FEATURE:
          case USB_REQUEST_SET_FEATURE:
              USBStdFeatureReqHandler();
              break;
          case USB_REQUEST_GET_INTERFACE:
              inPipes[0].pSrc.bRam = (uint8_t*)&USBAlternateInterface[SetupPkt.bIntfID];  // Set source
              inPipes[0].info.bits.ctrl_trf_mem = USB_EP0_RAM;               // Set memory type
              inPipes[0].wCount.v[0] = 1;                         // Set data count
              inPipes[0].info.bits.busy = 1;
              break;
          case USB_REQUEST_SET_INTERFACE:
              inPipes[0].info.bits.busy = 1;
              USBAlternateInterface[SetupPkt.bIntfID] = SetupPkt.bAltID;
              break;
          case USB_REQUEST_SET_DESCRIPTOR:
              USB_SET_DESCRIPTOR_HANDLER(EVENT_SET_DESCRIPTOR,0,0);
              break;
          case USB_REQUEST_SYNCH_FRAME:
          default:
              break;
      }//end switch
  }//end USBCheckStdRequest
  
  /********************************************************************
   * Function:        void USBStdFeatureReqHandler(void)
   *
   * PreCondition:    None
   *
   * Input:           None
   *
   * Output:          Can alter BDT entries.  Can also modify USB stack
   *                  Maintained variables.
   *
   * Side Effects:    None
   *
   * Overview:        This routine handles the standard SET & CLEAR
   *                  FEATURES requests
   *
   * Note:            This is a private function, intended for internal 
   *                  use by the USB stack, when processing SET/CLEAR
   *                  feature requests.  
   *******************************************************************/
  static void USBStdFeatureReqHandler(void)
  {
      BDT_ENTRY *p;
      EP_STATUS current_ep_data;
      #if defined(__C32__)
          uint32_t* pUEP;
      #else
          unsigned char* pUEP;             
      #endif
      
  
      #ifdef	USB_SUPPORT_OTG
      //Check for USB On-The-Go (OTG) specific requests
      if ((SetupPkt.bFeature == OTG_FEATURE_B_HNP_ENABLE)&&
          (SetupPkt.Recipient == USB_SETUP_RECIPIENT_DEVICE_BITFIELD))
      {  
          inPipes[0].info.bits.busy = 1;
          if(SetupPkt.bRequest == USB_REQUEST_SET_FEATURE)
              USBOTGEnableHnp();
          else
              USBOTGDisableHnp();
      }
  
      if ((SetupPkt.bFeature == OTG_FEATURE_A_HNP_SUPPORT)&&
          (SetupPkt.Recipient == USB_SETUP_RECIPIENT_DEVICE_BITFIELD))
      {
          inPipes[0].info.bits.busy = 1;
          if(SetupPkt.bRequest == USB_REQUEST_SET_FEATURE)
              USBOTGEnableSupportHnp();
          else
              USBOTGDisableSupportHnp();
      }
  
      if ((SetupPkt.bFeature == OTG_FEATURE_A_ALT_HNP_SUPPORT)&&
          (SetupPkt.Recipient == USB_SETUP_RECIPIENT_DEVICE_BITFIELD))
      {
          inPipes[0].info.bits.busy = 1;
          if(SetupPkt.bRequest == USB_REQUEST_SET_FEATURE)
              USBOTGEnableAltHnp();
          else
              USBOTGDisableAltHnp();
      }
      #endif   //#ifdef USB_SUPPORT_OTG 
  
      //Check if the host sent a valid SET or CLEAR feature (remote wakeup) request.
      if((SetupPkt.bFeature == USB_FEATURE_DEVICE_REMOTE_WAKEUP)&&
         (SetupPkt.Recipient == USB_SETUP_RECIPIENT_DEVICE_BITFIELD))
      {
          inPipes[0].info.bits.busy = 1;
          if(SetupPkt.bRequest == USB_REQUEST_SET_FEATURE)
              RemoteWakeup = true;
          else
              RemoteWakeup = false;
      }//end if
  
      //Check if the host sent a valid SET or CLEAR endpoint halt request.
      if((SetupPkt.bFeature == USB_FEATURE_ENDPOINT_HALT)&&
         (SetupPkt.Recipient == USB_SETUP_RECIPIENT_ENDPOINT_BITFIELD)&&
         (SetupPkt.EPNum != 0) && (SetupPkt.EPNum <= USB_MAX_EP_NUMBER)&&
         (USBDeviceState == CONFIGURED_STATE))
      {
  		//The request was valid.  Take control of the control transfer and
  		//perform the host requested action.
  		inPipes[0].info.bits.busy = 1;
  
          //Fetch a pointer to the BDT that the host wants to SET/CLEAR halt on.
          if(SetupPkt.EPDir == OUT_FROM_HOST)
          {
              p = (BDT_ENTRY*)pBDTEntryOut[SetupPkt.EPNum];
              current_ep_data.Val = ep_data_out[SetupPkt.EPNum].Val;
          }
          else
          {
              p = (BDT_ENTRY*)pBDTEntryIn[SetupPkt.EPNum];
              current_ep_data.Val = ep_data_in[SetupPkt.EPNum].Val;
          }
  
          //If ping pong buffering is enabled on the requested endpoint, need 
          //to point to the one that is the active BDT entry which the SIE will 
          //use for the next attempted transaction on that EP number.
          #if (USB_PING_PONG_MODE == USB_PING_PONG__ALL_BUT_EP0) || (USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG)   
              if(current_ep_data.bits.ping_pong_state == 0) //Check if even
              {
                  USBHALPingPongSetToEven(&p);
              }
              else //else must have been odd
              {
                  USBHALPingPongSetToOdd(&p);
              }
          #endif
          
          //Update the BDT pointers with the new, next entry based on the feature
          //  request
          if(SetupPkt.EPDir == OUT_FROM_HOST)
          {
              pBDTEntryOut[SetupPkt.EPNum] = (volatile BDT_ENTRY *)p;
          }
          else
          {
              pBDTEntryIn[SetupPkt.EPNum] = (volatile BDT_ENTRY *)p;
          }
  
  		//Check if it was a SET_FEATURE endpoint halt request
          if(SetupPkt.bRequest == USB_REQUEST_SET_FEATURE)
          {
              if(p->STAT.UOWN == 1)
              {
                  //Mark that we are terminating this transfer and that the user
                  //  needs to be notified later
                  if(SetupPkt.EPDir == OUT_FROM_HOST)
                  {
                      ep_data_out[SetupPkt.EPNum].bits.transfer_terminated = 1;
                  }
                  else
                  {
                      ep_data_in[SetupPkt.EPNum].bits.transfer_terminated = 1;
                  }
              }
  
  			//Then STALL the endpoint
              p->STAT.Val |= _BSTALL;
              p->STAT.Val |= _USIE;
          }//if(SetupPkt.bRequest == USB_REQUEST_SET_FEATURE)
          else
          {
  			//Else the request must have been a CLEAR_FEATURE endpoint halt.
              #if (USB_PING_PONG_MODE == USB_PING_PONG__ALL_BUT_EP0) || (USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG)   
                  //toggle over the to the non-active BDT
                  USBAdvancePingPongBuffer(&p);  
  
                  if(p->STAT.UOWN == 1)
                  {
                      //Clear UOWN and set DTS state so it will be correct the next time
                      //the application firmware uses USBTransferOnePacket() on the EP.
                      p->STAT.Val &= (~_USIE);    //Clear UOWN bit
                      p->STAT.Val |= _DAT1;       //Set DTS to DATA1
                      USB_TRANSFER_TERMINATED_HANDLER(EVENT_TRANSFER_TERMINATED,p,sizeof(p));
                  }
                  else
                  {
                      //UOWN already clear, but still need to set DTS to DATA1     
  					p->STAT.Val |= _DAT1;
                  }
  
                  //toggle back to the active BDT (the one the SIE is currently looking at
                  //and will use for the next successful transaction to take place on the EP
                  USBAdvancePingPongBuffer(&p);    
                  
                  //Check if we are currently terminating, or have previously terminated
                  //a transaction on the given endpoint.  If so, need to clear UOWN,
                  //set DTS to the proper state, and call the application callback
                  //function.
                  if((current_ep_data.bits.transfer_terminated != 0) || (p->STAT.UOWN == 1))
                  {
                      if(SetupPkt.EPDir == OUT_FROM_HOST)
                      {
                          ep_data_out[SetupPkt.EPNum].bits.transfer_terminated = 0;
                      }
                      else
                      {
                          ep_data_in[SetupPkt.EPNum].bits.transfer_terminated = 0;
                      }
                      //clear UOWN, clear DTS to DATA0, and finally remove the STALL condition     
                      p->STAT.Val &= ~(_USIE | _DAT1 | _BSTALL);  
                      //Call the application event handler callback function, so it can 
  					//decide if the endpoint should get re-armed again or not.
                      USB_TRANSFER_TERMINATED_HANDLER(EVENT_TRANSFER_TERMINATED,p,sizeof(p));
                  }
                  else
                  {
                      //clear UOWN, clear DTS to DATA0, and finally remove the STALL condition     
                      p->STAT.Val &= ~(_USIE | _DAT1 | _BSTALL); 
                  } 
              #else //else we must not be using ping-pong buffering on the requested endpoint
                  //Check if we need to call the user transfer terminated event callback function.
                  //We should call the callback, if the endpoint was previously terminated,
                  //or the endpoint is currently armed, and the host is performing clear
                  //endpoint halt, even though the endpoint wasn't stalled.
                  if((current_ep_data.bits.transfer_terminated != 0) || (p->STAT.UOWN == 1))
                  {
                      //We are going to call the user transfer terminated callback.
                      //Clear the flag so we know we took care of it and don't need
                      //to call it again later.
                      if(SetupPkt.EPDir == OUT_FROM_HOST)
                      {
                          ep_data_out[SetupPkt.EPNum].bits.transfer_terminated = 0;
                      }
                      else
                      {
                          ep_data_in[SetupPkt.EPNum].bits.transfer_terminated = 0;
                      }
   
                      //Clear UOWN and remove the STALL condition.   
                      //  In this case we also need to set the DTS bit to 1 so that
                      //  it toggles to DATA0 the next time the application firmware
                      //  calls USBTransferOnePacket() (or equivalent macro).  
                      p->STAT.Val &= ~(_USIE | _BSTALL);  
                      p->STAT.Val |= _DAT1;
                      //Let the application firmware know a transaction just
                      //got terminated by the host, and that it is now free to
                      //re-arm the endpoint or do other tasks if desired.                                        
                      USB_TRANSFER_TERMINATED_HANDLER(EVENT_TRANSFER_TERMINATED,p,sizeof(p));
                  }
                  else
                  {
                      //Clear UOWN and remove the STALL condition.   
                      //  In this case we also need to set the DTS bit to 1 so that
                      //  it toggles to DATA0 the next time the application firmware
                      //  calls USBTransferOnePacket() (or equivalent macro).  
                      p->STAT.Val &= ~(_USIE | _BSTALL);  
                      p->STAT.Val |= _DAT1;
                  } 
              #endif //end of #if (USB_PING_PONG_MODE == USB_PING_PONG__ALL_BUT_EP0) || (USB_PING_PONG_MODE == USB_PING_PONG__FULL_PING_PONG)   
              
  			//Get a pointer to the appropriate UEPn register
              #if defined(__C32__)
                  pUEP = (uint32_t*)(&U1EP0);
                  pUEP += (SetupPkt.EPNum*4);
              #else
                  pUEP = (unsigned char*)(&U1EP0+SetupPkt.EPNum);
              #endif
  
  			//Clear the STALL bit in the UEP register
              *pUEP &= ~UEP_STALL;            
          }//end if(SetupPkt.bRequest == USB_REQUEST_SET_FEATURE)
      }//end if (lots of checks for set/clear endpoint halt)
  }//end USBStdFeatureReqHandler
  
  
  /** EOF USBDevice.c *****************************************************/
  